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Cortisol Levels Blood Test

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Cortisol Levels Blood Test What is cortisol? Cortisol, also referred to as hydrocortisone Compound F, is the biggest glucocorticoid hormone produced in the adrenal cortex. Cortisol is very involved in the control of calcium absorption, gastric acid and pepsin secretion. It is also highly involved in the maintenance of blood pressure, anti-inflammatory function, gluconeogenesis, and immune function. The production of Cortisol has a circadian rhythm. Its levels tend to rise to its highest point in the early morning and then, at night, they drop to the lowest concentration. Levels increase independently of circadian rhythm in reaction to stress. Elevated cortisol production is associated with Cushing’s syndrome and adrenal tumors; on the other hand, decreased cortisol production is related with adrenal insufficiency, commonly to a condition called Addison’s disease. Besides it is also associated to adrenocorticotropic hormone (ACTH) deficiency. Cortisol is a strong hormone also called glucocorticoid that influence the metabolism of carbohydrates, proteins, and fats, but mainly the process of glucose. One of the functions of cortisol is to increase blood sugar levels by stimulating the secrec tion of glucose from glucose deposits in cells. Additionally, cortisol acts to inhibit insulin, thereby affecting glucose streaming into cells.

Cortisol Levels Blood Test

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Cortisol Levels Blood Test

What is cortisol?


Cortisol, also referred to as hydrocortisone Compound F,  is the biggest glucocorticoid hormone produced in the adrenal cortex. Cortisol is very involved in the control of calcium absorption, gastric acid and pepsin secretion. It is also highly involved in the maintenance of blood pressure, anti-inflammatory function, gluconeogenesis, and immune function.  The production of Cortisol has a circadian rhythm.  Its levels tend to rise to its highest point in the early morning and then, at night, they drop to the lowest concentration. Levels increase independently of circadian rhythm in reaction to stress. Elevated cortisol production is associated with Cushing’s syndrome and adrenal tumors; on the other hand, decreased cortisol production is related with adrenal insufficiency, commonly to a condition called Addison’s disease. Besides it is also associated to adrenocorticotropic hormone (ACTH) deficiency.
Cortisol is a strong hormone also called glucocorticoid that influence the metabolism of carbohydrates, proteins, and fats, but mainly the process of glucose. One of the functions of cortisol is to increase blood sugar levels by stimulating the secrec tion of glucose from glucose deposits in cells. Additionally, cortisol acts to inhibit insulin, thereby affecting glucose streaming into cells.

The periodic process of production of cortisol is controlled by different areas in the body. These are: the hypothalamus (an area of the brain), the pituitary gland (also called the "master gland"), and the adrenal glands. A hormone called corticotrophin or CRH is released after it is formed in the hypothalamus. Afterwards, CRH stimulates the pituitary to begin this journey in which adrenocorticotropic hormone (ACTH) is also produced. The creation of ACTH that is generated stimulates a section of the adrenal glands. This area is known as the adrenal cortex to produce cortisol. Rising levels of cortisol usually represent a negative feedback to curtail regular and consistent production of CRH and ACTH, needed to complete an elaborate feedback mechanism.
Blood and urine are the two ways in which cortisol can be measured. The most reliable method to evaluate the release of cortisol is the 24-hour urine sample collection. However, when blood levels are requested by the physician, the process to measure plasma cortisol consists of taking samples once in the morning and again in the afternoon. It is common that cortisol levels rise and drop during the day, this process is called a diurnal variation, therefore cortisol is at its peak level between 6 and 8 in the morning. It then starts falling gradually, getting to its lowest point around 12 AM. A doctor will usually order a blood cortisol levels test instead of a 24-hour urine collection because the earliest sign of adrenal malfunction is the loss of this diurnal variation, even though the cortisol levels are not yet increasing at that time of the day. See it this way: people with Cushing's syndrome mostly have upper normal plasma cortisol levels in the morning and no reduction is normally detected as the day goes by.
Only 10 to 15% of cortisol in the blood is formed biologically or through a natural process in the body. The rest is attached to serum proteins.
Unbound serum cortisol accesses the saliva through intracellular mechanisms, once in the saliva a big part of cortisol continues not to bond with protein.
The amount of salivary cortisol is not directly affected by salivary flow rate or salivary enzymes. Medical and research often report high correlations between serum and saliva cortisol, demonstrating that salivary cortisol levels have an effect in the quantity of serum cortisol levels.
Cortisol is considered a very important hormone produced by the adrenal glands mainly when a person experiences stress. To measure the levels of cortisol is needed to take a blood test. This is a simple process that evaluates the levels of Cortisol in the blood to be later reviewed by your doctor.

Low and high cortisol levels
When cortisol levels are low, it might be a sign of adrenal insufficiency. There are several symptoms associated to this reduced result which can be part of adrenal insufficiency condition. These symptoms include low blood pressure, abdominal pain, fatigue, nausea, vomiting, etc.
If adrenal insufficiency is left untreated it can become a potential danger for your health, it can even be life threatening. Nonetheless there are milder forms you must have a blood test done.
When a person has elevated cortisol levels this is commonly associated with a condition known as Cushing's Syndrome/Disease. Cushing's syndrome is a condition in which the symptoms suffered by the patient go from elevated blood pressure and blood sugar (diabetes), to weight gain. The cortisol test is more often ordered to help diagnose low cortisol levels or adrenal insufficiency. A different type of test might be requested if your doctor is trying to scrap Cushing's syndrome.
Cortisol serum is also referred to as serum cortisol. It is a test that helps measure cortisol levels in the blood stream. Cortisol is a sterile hormone produced in the adrenal cortex. The hormone cortisol is generated in the body in response to a hormone called ACTH, which is produced by the pituitary glands.
A cortisol test is done to measure the level of the hormone cortisol in the blood. The cortisol level could reveal problems with the adrenal glands or pituitary gland in a patient. Cortisol is formed by the adrenal glands. Cortisol levels go up when the pituitary gland releases another hormone called adrenocorticotropic hormone (ACTH).
Cortisol has a wide variety of functions in different organs in the human body. It helps the body use sugar (glucose) and fat for energy (metabolism). In addition, it controls the way body manages stress. Cortisol levels can be altered by many conditions; the most commons are physical or emotional stress, vigorous activity, infections, or injury.
It is known that cortisol levels rise during the morning, especially very early. They can reach their highest levels about 7 a.m. They start falling until they become very low in the evening and during the first period of sleep. On the contrary, if someone sleeps during the day and stays up at night, this standard change may be reversed. If you do not have this daily change (diurnal rhythm) in cortisol levels, it is possible that your adrenal glands are overacting. This condition is called Cushing's syndrome.
In order to perform this blood test it is necessary to take two blood samples, one in the morning and a second one in the afternoon.
Cortisol hormone is vital in the metabolism of proteins, lipids, and carbohydrates. It has a big impact on blood glucose levels. Besides, cortisol helps maintain blood pressure as well as regulate the immune system. The majority of cortisol in the blood is bound to a protein; however there is a small percentage that moves freely. This group is biologically active. Free cortisol is excreted into the urine and is also present in the saliva. This test can determine the amount of cortisol in the blood, urine, or saliva.
The level of cortisol suffers a “diurnal variation”. This means that the blood levels rise and fall throughout the day. It reaches its peak level early in the morning; it then declines slowly during the following hours. To complete this pattern, it touches its lowest point at about midnight. This pattern can reverse when a person works irregular shifts (stays up all night) and sleeps at different times of the day. This common may be also altered when a disease or condition either limits or stimulates cortisol production.

To measure the level of cortisol hormone in the blood is needed to take a test, normally ordered by your primary care physician. Cortisol hormone high levels are a result of problems in the adrenal or pituitary gland. Adrenal gland produces hormone cortisol. The levels of the hormone cortisol increase when the hormone adrenocorticotropic (ACTH) is released by pituitary glands. The hormone cortisol functions in several ways. One of its most important labors in the human body is to dissolve the food in energy, process known as metabolism. Also, the cortisol hormone manages the body stress. That is why doing extreme physical activities, being under emotional stress, injuries, and infections may affect the levels of cortisol in the body. Early in the morning (around 7 a.m.) and in midday hours, level of cortisol rises. When the body is resting, commonly in the evening and in early sleep phase these levels go back to lower levels. This pattern may be altered if you sleep in day hours and keep yourself awake at night. Due to this pattern inconsistency, the test requires two blood samples: one must be taken in the morning and the other one in the afternoon. In some cases, your doctor will request to perform this test in combination with a 24 hour urine test.
Cortisol is produced and eventually secreted by the adrenal glands, a couple of organs in form of a triangle allocated right on top of the kidneys. This process is regulated by the hypothalamus in the brain and by the pituitary gland, a tiny organ located below the brain. When the blood cortisol level falls, the hypothalamus releases a substance called corticotrophin that also produces another hormone (CRH). It directs the pituitary gland to start creating a hormone called adrenocorticotropic (ACTH). This other hormone stimulates the adrenal glands to produce and release cortisol. For this to be completed and to assure that enough quantity of cortisol is produced, the hypothalamus along with the pituitary and adrenal glands must function without any abnormalities.
The group of signs and symptoms that are seen with an
When abnormal levels of cortisol are detected a doctor will diagnose a condition known as Cushing syndrome.
Cortisol production increases in the following situations:

  • ACTH-producing tumors, in the pituitary gland but they could also be found in other parts of the body
  • A major amount of adrenal glands being produced, due to a tumor or due to excessive growth of adrenal tissues (hyperplasia)

Lower levels of cortisol are produced when:

  • A pituitary gland has only minor activity or if a pituitary gland tumor inhibits ACTH production; when this happens it is considered as presence of secondary adrenal insufficiency.
  • Underactive or adrenal glands that have been damaged (adrenal insufficiency) that limit the amount of cortisol that is being produced; this is known as Addison disease and also referred to as primary adrenal insufficiency

Cortisol low levels


Even though it is not very common to hear about cortisol levels, specialists consider that having adequate levels of cortisol are essential to keep in good health and have a better quality of life. Actually, this fact has become a focus of doctors and other people involved in public health. Their goal is to help people using natural scientific methods. To get an idea of how important it is for your health you must know that cortisol is the foundation of the entire endocrine system. It is very important for our bodies to adapt to the demands of life; especially since it is linked to all other major hormones. Other thing to consider is that when a person does not make sufficient cortisol, their quality of life decreases. People with low levels of cortisol are not able to tolerate or benefit from the optimization of their thyroid gland, estrogens, DHEAS or even testosterone levels. Some doctors have realized that partial cortisol deficiency is common, mainly among women. This is a result of some research that analyzed patients with fatigue and pain with natural methods. The study included saliva tests for cortisol levels. After reviewing the results of the investigation they concluded that women have lower cortisol levels than men based on their reactions and responses to the effects of cortisol. A woman that suffers from cortisol deficiency is more prone to face a series of symptoms such as fatigue, anxiety, depression, and fibromyalgia. Women with low cortisol levels can also have autoimmune diseases. Throughout the years, studies have demonstrated a hypoactive hypothalamic-pituitary-adrenal system in persons with these conditions. Research has also revealed that some SSRI anti-depressants like Prozac, Paxil, and Lexapro have an effect on the brain that causes it to increase ACTH production and cortisol levels. They have concluded that this is the main reason why they alleviate so many different types of symptoms. This explains why it is so hard to stop taking them too. As you can see, many drugs consumed in large doses, represent a big chance that levels of cortisol will raise. Other drugs mentioned in the study are amphetamines, cocaine, ecstasy, nicotine, the polemic marijuana, and even caffeine. With this on the table, it is now easier to understand the fact that these drugs are so addictive. They are actually more addictive to persons with low cortisol levels and maybe this is why stop consuming these drugs is so hard.
The symptoms of partial cortisol deficiency and severe adrenal insufficiency are pretty similar. The first ones are a little less aggressive than the symptoms suffered by patients with severe adrenal deficiency. Some of them are fatigue, aches and pains, insomnia, recurring infections, low blood pressure, low stress tolerance, brain fog, allergies, anxiety, irritability, hypoglycemia, nausea, PMS/PMDD, autoimmune diseases, excessive sweating, teeth grinding, tired legs, hot flashes, etc. Sufferers feel like they often have the flu.
One of the most important cortisol's functions is to maintain the blood sugar level under control throughout the day. Hypoglycemia causes irritability, confusion, bad headaches, hot flashes, sweating, and palpitations; it can even lead to seizures. Hypoglycemia is as well a condition that affects a person sleep with anxiety and sweating. Additionally, cortisol deficiency is many times misdiagnosed when a person takes thyroid hormone. Someone with higher thyroid levels will have a more active metabolism and also more need for cortisol. In some cases, if a patient feels worse taking medicines to treat thyroid diseases that they need, they have an underlying cortisol loss. Women with estradiol and progesterone levels in the latter half of the menstrual cycle can see a blockage of cortisol's effects. In other words, cortisol deficiency is by far the cause of severe PMS/PMDD and of intolerance of estradiol and progesterone replacement in women in menopause. Symptoms like nausea and vomiting during early pregnancy months as well as post-partum depression have been associated with cortisol deficiency too. However, they have improved after consuming medications to balance levels of cortisol. Cortisol supplementation is also prescribed to help improve mood, energy, mental functioning, sleep quality and the ability to handle physical and emotional stress. Besides, it helps treat allergies and autoimmune diseases. As can appreciate, it is vital to keep cortisol levels in optimal status.
The most common form of this foundational hormone decrease is partial central adrenal insufficiency due to inadequate ACTH production. Low levels of cortisol are not diagnosable by current conventional testing. Usually, doctors think that all cortisol deficiency is Addison's Disease. However, the problem rarely lies in failure of the adrenal glands. Mostly it happens because the brain-hypothalamic-pituitary system is not secreting a right amount of ACTH throughout the day to stimulate sufficient cortisol production by the adrenals.

Cortisol blood test
The screening test for cortisol deficiency is a common procedure; in some places is called a serum AM cortisol test. This procedure is insensitive for a several reasons. It's reported with a reference range of 5 to 20mcg/dL. For some doctors a result under 14mcg/dL is considered suspicious. Around the world, physicians believe that they can rule the test for cortisol in or out with an ACTH stimulation test. This is absolutely wrong. We are talking about a physiological test that basically proves that the adrenal glands can make normal AM amounts of cortisol under maximal stimulation. The ACTH stimulation test is out of parameters only in cases of nearly complete pituitary or adrenal gland failure. It is qualified as normal in the much more common partial central cortisol deficiency.
To diagnose cortisol deficiency the physician needs to have two facts into account. First doctors must evaluate the symptoms and then review the free cortisol levels. A serum cortisol test allows a doctor to see the total cortisol in the blood of a patient; however this level is affected by the amount of cortisol-binding globulin. Serum free cortisol levels may be checked at some laboratories, but it is not possible to know your cortisol level before taking the test. The best way to test free cortisol levels is in the blood throughout the day. Another option is a diurnal salivary cortisol profile. Normally, the patient is able to collect samples at home during a normal day. The accuracy of saliva cortisol testing is very reliable. In despite of it, most doctors do not recommend or order saliva testing. The majority of labs often report statistical ranges under zero, something incompatible with health. This means that physicians do not really have an easy way to test the low free cortisol levels in their patients with fatigue, chronic pain, depression, and hypoglycemia. Even if physicians think that a patient might have cortisol deficiency, they restrain themselves to prescribe cortisol. There is very little experience with cortisol replacement, but there has been a lot of talk and analysis regarding the damaging effects of pharmacologic doses of popular non-natural “steroids” (e.g. prednisone, dexamethasone). This negative experience with cortisol supplementation has been hardly misunderstood and assimilated. They are afraid that any dose of cortisol taken during a long period of time will cause negative effects like Cushing's syndrome. Sadly, they are not far from reality, since they do not fully understand the importance of DHEA. Oral glucocorticoid therapy, whether it is hydrocortisone (HC) or a powerful artificial steroid, suppresses ACTH production and obviously the production of DHEA. In these cases the next problem is a severe deficiency of a major anabolic hormone. DHEA is something to keep an eye on since it is considered the body's natural cortisol antagonist. Its mission is to prevent many of the negative effects of cortisol. Also, DHEA has anabolic effects through conversion to estradiol and testosterone within organs’ tissues throughout the human body. Although DHEA is practically unknown to conventional medicine, it certainly is the most abundant steroid hormone in the body with almost 20 times more presence in the human body than cortisol. Besides, it is found 8000 times more than estradiol or testosterone. There are thousands of analysis and investigations around it. They detail its contributions to health and the consequences of not producing a valid value of it. For instance, studies have proven that women on 10mg of prednisone daily may gain more bone mass when given DHEA. This is just another example of the use and misuse of pharmaceutical hormone substitutes, fact that many doctors do not see as benefits and safety of balanced hormone restoration. Some even prefer sublingual DHEA because it delivers more of the active hormone into the circulation of the blood. People taking cortisol or any artificial steroid have to assure that their average DHEAS levels will restore to those of a young person of the same sex: around 200mcg/dL in women, 300mgc/dL in men. This process normally takes 10 to 25mg of sublingual DHEA for women, 25 to 50mg for men. If DHEA is swallowed, the dose needs to be 25 to 50% higher.
When someone is under physiological cortisol supplementation accompanied by DHEA may not suffer any negative effects. Since HC produces much more fluid accumulation than the artificial steroids, it is a lot easier to tell when an overdose occurs. In a case like this, a person will notice fluid retention, weight gain, facial puffiness, higher blood pressure and increased blood sugar. To prevent these symptoms to affect you try to look out for these signs and reduce the dose if they have manifested.
In comparison with other artificial steroids, HC is short-acting, which results helpful when trying to avoid overdosing. Dr. Jefferies popularized the beliefs that healthy people must not take only 20 to 30mg of HC daily. Conventional medicine allows doses up to 20 to 35mg/day to Addison's disease patients. People that suffer central cortisol insufficiency are in special need to fully replace doses too. This is because each and every dose they take as time passes, the effects suppress their already slow and weak ACTH production. Higher cortisol doses are the best option in persons who are substituting their DHEA, as they must, and in those who are taking thyroid hormone since both of these oppose cortisol strongly. However, there are people that need 40-60mg/day. Cortisol supplementation, when taken in its lowest dose, provides full clinical benefits, and what is more remarkable is that cortisol combined with DHEA replacement is a good medical practice. It is always more effective and also much safer for inflammatory problems than the steroid intake and non-steroidal anti-inflammatory medicines that some doctors prescribe every day. This group include prednisone, methotrexate, Motrin®, Enbrel®, Humira®, Mobic®, etc.)
The process to have Plenadren someday is advancing. This will significantly simplify cortisol replacement with a one a day tablet that provides both a fast and consistent release of cortisol and a less aggressive release over 24 hrs. A well recommended oral HC replacement therapy is somehow a pulse therapy. With a first dose of the immediate release HC tablets, cortisol levels peak after one hour into super physiological levels, afterwards they drop drastically to pre-dose levels in several hours. The length of time depends upon the dose and the time of day in which it is consumed. The best thing to do, according to specialist, is to take the largest dose upon awakening, about half that dose around noon, and half of the lunch dose at night or when eating dinner, if needed. Another half dose may be taken at bedtime. Though it is preferably to take them only during the day if it works as the patients’ ACTH-cortisol production, the effects will still work overnight; this can help with suppression of endogenous production.

In many cases HC dosing must be guided by symptoms, seeking the lowest doses that eliminate any side effects, like saliva testing when is accurate if a person is swallowing HC tablets and can be used to adjust the HC doses. Saliva tests might not be accurate if a person is taking the HC sublingually or transdermal. While one can use ZRT's ranges or other use variable ranges. Saliva cortisol levels right before an oral test is performed change the dose, which should be low or around the normal range. Sometimes it can be a bit low for that time of day, considering that the level was much higher for a couple hours after the dose taken previously. This is easy to understand if we consider a saliva cortisol level prior to the noon or dinner doses is high to normal or high for that time of day. However, the levels should decrease after the previous dose. On the other hand the cortisol dose can result too low if a peak saliva cortisol level at 1 in the afternoon up until 2 hours after a dose is normal. Do not forget that it will be much lower after 3 or 4 hours have gone by, by the time the next dose is due. If someone is taking HC, the awakening saliva cortisol, even before taking the first dose, will show the amount of cortisol that they are making on their own, because the dose that must be taken before going to bed will be long gone. If the saliva cortisol quantity detected in the morning before taking HC is very low, it is marked as a suppression of their own ACTH/cortisol production. This could be still fine if that HC regimen is enough for that person. The patient, though, will need to be more careful to stress dose and not to miss any of the doses scheduled daily. Since most cortisol insufficiency is central, the oral HC doses in some patients may easily suppress an ACTH production that is catalogued as weak. The number of people and the amount of HC and the number of doses that they need needs to be monitored. Each person has different metabolism and daily routines so they each have to find out the specific doses that will fit their health needs. Once they figure this out it will be easy to eliminate their cortisol-deficiency and obviously the symptoms associated. Have in mind that the level has got to always be the lowest dose without being ineffective.
Mild cortisol insufficiency, even if it has been diagnosed after a test, rarely requires cortisol supplementation. A person is able to reduce their demand for cortisol considerably by taking steps to reduce or, if possible, eliminate stress in their life. This includes getting a good night's sleep, leaving spare time to spend with family and do recreational activities. Also, it is important to practice daily exercise and make sure to have an adequate nutrition, preferably by taking supplements, eliminating any foods from their diet that can cause allergies, like gluten, dairy, soy, eggs, etc. Another thing that can help a lot is visit a doctor to identify and treat any ongoing infections that might be affecting the proper function of their organs (root canal, H. Pylori, intestinal symbiosis). Try to consult physicians specialized in functional medicine to help with these health problems.

Why someone must take a cortisol test
A serum cortisol test is taken to evaluate how well the adrenal and pituitary glands are working. This test is essential in the diagnosis of several adrenal and pituitary gland related diseases. When a result from this test is between 6 to 23 mcg/dL (micrograms per deciliter) ranges, the doctor will consider this result normal. This is a very well accepted range in despite of each laboratory variation, which usually are higher or lower by a unit or two. Remember this is the cortisol level of a normal result that has been tested at or before 8 in the morning.
Any result higher than 23 mcg/dL will be qualified as an increased cortisol level, and could be an indicative of diseases like adrenal tumor, Ectopic, ATH tumors or Cushing's syndrome. On the contrary if the result is under 6 mcg/dL it is a clear sign of bad conditions like hypopituitarism and Addison's disease.
When doctors suspect that a patient may be suffering ectopic Cushing's syndrome, pituitary Cushing's syndrome or an acute adrenal crisis, they also order this test.
In addition, a cortisol test is done to find problems of the pituitary gland or adrenal glands, such as the accelerated production of hormones or the opposite.

How you need to prepare for the test
Normally, you will be asked to avoid strenuous physical activity the day before a cortisol test. You may also be asked to lie down and relax for 30 minutes right before the blood test sample is drawn.
Your doctor will tell you that many medications may change the results of this test. Some medicines, such as steroids, can affect cortisol levels. This has a long lasting effect. This means that even months after you stop taking the medicine the levels will be irregular. Be sure to tell your physician about all the nonprescription and prescription medicines you are taking when the test is ordered.
Also, always communicate with your doctor about any concerns you have regarding the need for the test, the risks related with the procedure, the way it is performed and what the results represent to your future well-being.
As explained before, a cortisol test is normally ordered to screen and treat the symptoms of Cushing syndrome. You can identify this condition if you are having signs and symptoms associated with large amount of cortisol intake. Blood cortisol testing checks levels of both protein-bound and free cortisol; as an alternate option, urine analysis evaluates only free cortisol, which should correlate with the levels of free cortisol in the blood. In some cases doctors will also order a salivary cortisol sample to be tested as this is another method to detect Cushing syndrome as well.
Blood cortisol is also used to help diagnose adrenal insufficiency and Addison disease; in patients with these conditions the adrenal glands do not function properly.
Many ranges of blood and saliva cortisol levels may be collected at different times, for example at 8 in the morning and 4 later in the day. The samples can be used to evaluate both cortisol concentrations and the dynamic diurnal variation. As a natural mechanism, the level of cortisol in the blood rises and decreases in a process called diurnal variation. This pattern peaks early in the morning to continue decreasing throughout the day until it reaches its lowest level about midnight. Due to this interactive bounce a 24-hour urine cortisol sample will not show diurnal variation; it will only measure the total amount of unbound cortisol excreted in 24 hours.
If an abnormal level of cortisol is detected, a doctor will do additional testing to help confirm the primary results and as a reliable tool to determine what is causing it.

Alternate tests for cortisol
If a person has a high cortisol level, a doctor is probably want to have him or her a dexamethasone suppression test to help determine whether the cause of the elevation is related to excess ACTH production by the pituitary gland. To get accurate results, this test involves analyzing a baseline sample for cortisol; the person is then required to take dexamethasone (a synthetic glucocorticoid) to continue measuring cortisol levels in subsequent timed samples. Dexamethasone inhibits ACTH production and is supposed to decrease cortisol production if the reason causing the excess is pituitary-related. However, there are a few variations of this test. Sometimes, an overnight test may be used to help screen for Cushing syndrome. Also, longer tests are usually done to confirm initial findings. Under this series of tests, the medication is given (either low or high dose) every 6 hours for either 2 or 4 days prior to blood or urine collection. As a backup reference, separate 24-hour urine samples are collected prior to the testing period and while sample is being taken. Afterwards, the blood and urine samples are measured for cortisol and evaluated. If the cortisol reports of the initial blood or urine tests, or both indicate insufficient cortisol production, you may need to have an ACTH stimulation test done. This stimulation test consists of measuring the concentration of cortisol in a person's blood before and after an injection of synthetic ACTH. If after the injections the adrenal glands are damaged or not functioning properly, the response will be limited. If they are functioning normally, then cortisol levels will elevate with the ACTH stimulation. A longer version of this test that can be performed on a period of up to 3 days is usually recommended to help distinguish between adrenal and pituitary insufficiency.

When to take a cortisol test?
Facts like when and how often laboratory tests are done obeys to many factors. The frequency of laboratory tests will always depend on the results or completion of other tests done previously within a year period also other procedures and treatments may have an effect on this. Lab tests are performed immediately in an emergency, or they may be put off as a diagnosed sickness is treated or monitored. A test may be suggested or when certain signs or symptoms appear. If conditions worsen the test becomes necessary.
Lab tests may need to be performed at a certain time of day. This is because due to changes in the natural way your body functions through the course of a day and the activities you are up to. In situations where you have prepared for a test by changing your food or fluid intake, blood and urine tests will be timed in accordance with those restrictions. Timing of tests may as well be based on increased and decreased levels of medications, drugs or other substances in the body.
Other factors that influence when and how often a lab test is required include age or gender of the person being tested. Chronic or progressive conditions may need ongoing monitoring through the use of lab tests. Patients with conditions that worsen and improve may also need frequent medical observation. A few blood tests may be repeated to gather a series of results, or they may need to be repeated to confirm or disregard certain results. Sometimes tests are ordered for professional or legal reasons. Time and frequency for these tests is also a priority.
A cortisol test is going to be ordered when a person has symptoms that suggest a high level of cortisol and a condition known as Cushing syndrome. These signs include the following:

  • Muscle wasting and weakness
  • Osteoporosis
  • Hypertension or high blood pressure
  • Glucose or high blood sugar
  • Obesity, especially in the stomach
  • Fragile skin
  • Purple streaks on the abdomen

This test will be ordered when someone has symptoms that may be consequence of a low level of cortisol, adrenal insufficiency or Addison disease. Here are some examples:

  • Fatigue
  • Low blood pressure
  • Weight loss
  • Muscle weakness
  • Abdominal pain
  • Dark patches of skin (normally present when patients has Addison disease)

In some cases, a very low production of cortisol combined with a stressor can cause an adrenal crisis that can be life-threatening and will need urgent medical attention. Symptoms of a crisis that will require the patient to receive immediate medical care are:

  • Low blood pressure (hypotension)
  • Severe pain in the lower back, abdomen, or legs
  • Vomiting and diarrhea, resulting in dehydration
  • Loss of consciousness

Suppression or stimulation testing is ordered when initial results are abnormal. Cortisol testing may be ordered at intervals after a diagnosis of Cushing syndrome or Addison disease to monitor the effectiveness of treatment.
Specific symptoms in women include having irregular menstrual periods and increased growth of facial hair. In children, you can see short stature and delayed development.

How do I prepare for a cortisol test?
Cortisol serum test is a blood test, so preparation will mostly include going off any prescription drugs that you are consuming and that may affect cortisol levels.
Drugs which cause an increase in cortisol levels include estrogens, synthetic glucocorticoids. Others can result in decreased cortisol levels such as are androgens like phenytoin.
Most of the time the patient will prefer to have the test done early in the morning if the test requires fasting (avoid any foods or drinks hours before the blood sample is drawn).

How is the cortisol test done?
This is a blood test, therefore a blood sample will be drawn usually from the vein inside the elbow or from the back of the hand. To start, the vein area is cleaned with an antiseptic and an elastic band is constrainedly wrapped around the upper arm to pursue more pressure and fill the vein with blood to make it easier to see. In other words, this makes the vein swell out prominently, making it easier to spot it and take the sample from it. Once the vein is located, a needle is inserted into the swollen vein and blood is collected into a tube or an airtight vial attached at the end of the needle.
As the needle is inserted and while blood is being collected, the band is removed from the arm to release the flow of blood. Once the vial is full, the needle is extracted and a piece of cotton is placed over the area for the person conducting the test to hold a piece of cotton tightly on it to stop any further bleeding. You can remove the cotton or gauze and a tiny little plaster will be placed on it. In most cases, you will experience a small twinge like an ant bite when the needle is inserted and the area from where the blood is drawn might throb for a while after the test. However, the process is totally non painful.
Afterwards, the vial must be shut tight and labeled appropriately. When the patient is too weak he or she might express feeling a little woozy because of the loss of blood. In such cases, it is imperative to drink some citrus fluids after the blood test, for example sweet lime, which is especially considered very effective combating dizziness after a blood test.


For this blood test, blood will be drawn from a vein in the arm, although sometimes urine or saliva may also be tested. Cortisol blood tests may be performed at about 8 am, when cortisol supposedly reaches its peak level, and one more time at about 4 pm, when the level will have dropped significantly. Sometimes an extra sample could be drawn late in the evening or towards midnight to measure cortisol at the time of the day when it normally gets to its lowest concentration in the blood. Obtaining more than one sample allows the doctor to monitor the daily pattern of cortisol secretion, which is called the diurnal variation.
Often, urine is tested for cortisol too; this test requires collecting all of the urine produced within a 24 hour period (during a complete day and night) but sometimes it is done on a single sample of urine collected in the morning. A 24-hour urine test is used more often than a cortisol blood test to diagnose Cushing's syndrome.
Cortisol testing can also be done in saliva. Normally, this type of cortisol test is collected between 11 pm and 12 am (midnight); at this time of the day the levels of cortisol are normally at their lowest. The saliva sample is collected by inserting a swab into the mouth and placing it there for a few minutes while the swab gets saturated with saliva.
You must follow your doctor's instructions regarding timing of sample collection, rest before test is performed, and any other specific pre-test preparation recommendations.
Normally, a saliva test requires special care in obtaining the sample. Other pre-test requirements can be stop eating and drinking, as well as not to brush your teeth for a period of time (usually between 15 to 30 minutes) prior to the saliva sample process. Make sure to follow any specific instructions you are given.
Have in mind that a stimulation or suppression test requires that you have a baseline blood sample drawn before you are given a particular amount of drug. Succeeding blood samples are drawn at specified times along the day.
Steps to take for a blood test:

  • Wrap an elastic band around your upper arm to stop the flow of blood. This helps make the veins below the band larger so it is easier to put a needle into the vein.
  • Clean the needle site with alcohol.
  • Put the needle into the vein. In some cases, more than one needle stick may be needed.
  • Attach a tube to the needle to fill it with the blood sample or samples.
  • Remove the band from your arm once enough blood has been collected.
  • Put a gauze pad or cotton ball over the needle site as the needle is removed.
  • Put pressure to the site and then a bandage to avoid further bleeding.

Rarely the results may not be helpful or a patient may not be able to have the test if he or she is experiencing one or more of the situations below:

  • Eating, drinking, or exercising before the test.
  • Having low blood sugar (hypoglycemia).
  • Having physical or emotional stress.
  • Being pregnant. This can cause urine cortisol levels to be high.
  • Taking medicines, such as birth control pills, estrogen, amphetamines, or corticosteroids.
  • Having a radioactive scan within 1 week of a cortisol test.

Other tests that can help determine if the pituitary gland or adrenal glands are functioning properly to assure your well-being include the adrenocorticotropic hormone (ACTH) stimulation test and dexamethasone suppression test. The ACTH stimulation test is the normal process to go for when Addison's disease is suspected.

How to understand the results

Remember that cortisol levels are very low at bedtime and at their highest just after waking, though this pattern will vary if a person works irregular shifts (overnight) and sleeps during the day.
An easy way to diagnose Cushing syndrome is if a person has increased or normal cortisol concentration in the morning and that level does not drop in the afternoon and evening since that is an indication of an overproduction of cortisol. When this excess of cortisol is detected it can be suppressed during a dexamethasone suppression test, showing if that the extra cortisol is due to increased pituitary ACTH production. If suppression is not achieved, the increased cortisol could be due to an ACTH-producing tumor outside of the pituitary. Other causes are a problem with the adrenal gland, or due to a medication, such as corticosteroids that may be prescribed to persons that suffer of asthma.
If insufficient cortisol is detected and the person tested reacts favorably to an ACTH stimulation test, then the problem is likely to be an abnormal ACTH production by the pituitary. If the person does not respond well to the ACTH stimulation test, then it is more likely that the problem is generated in the adrenal glands. If the adrenal glands are underactive, due to pituitary dysfunction which can be due to insufficient ACTH production, the diagnose will be labeled as secondary adrenal insufficiency. If decreased cortisol production is being caused by adrenal damage, the patient will usually be diagnosed with primary adrenal insufficiency or Addison disease.
Following cases where an abnormality has been identified and associated with the pituitary gland, adrenal glands, or other cause, doctors may use other testing such as CT (computerized tomography) or MRI (magnetic resonance imaging) scans to locate the source of the excess in the body. The focus areas are the pituitary and adrenal glands, or other tumor. Before proceeding doctors need to evaluate the extent of any damage to the glands.

Normal results
A cortisol test is done to measure the level of the hormone cortisol in the blood. The normal values listed below can be used as a guide but the amounts may just be a reference. These ranges vary from lab to lab, and your lab may have a different range for what is considered normal. Your lab report should contain the range your lab uses so you can review it as reference. Also, your doctor will have in consideration your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab, according to the mentioned factors.





5-23 micrograms per deciliter (mcg/dL) or 138-635 nanomoles per liter (nmol/L)


3-16 mcg/dL or 83-441 nmol/L



2-11 mcg/dL or 55-304 nmol/L

High values

  • A high cortisol level is a factor that helps diagnose Cushing's disease, a condition originated by a noncancerous tumor of the pituitary gland (adenoma). An adenoma causes the pituitary gland to make too much of the hormone adrenocorticotropic hormone (ACTH), which as a reactions makes the adrenal glands produce too much cortisol.
  • A high blood cortisol level can also be consequence of severe liver or kidney disease, depression, hyperthyroidism, or obesity.
  • Another condition derived from high level of cortisol in the blood is Cushing's syndrome, a disorder that can be caused by overactive adrenal glands, an adrenal gland tumor, some types of cancer, or long-term use of corticosteroids.
  • Pregnancy or birth control pills are as well a cause of high blood cortisol level.
  • Among other conditions that can rise cortisol levels are recent surgery, illness, injury, or whole-body infection (sepsis).

Adults have slightly higher cortisol levels than children do.

Low values

  • On the other hand side, a low level of cortisol in the blood is associated to Addison's disease, which is caused by damage to the adrenal glands. If the pituitary gland is not working as it should in a healthy body, it leads to low levels of the hormone ACTH. This then causes low levels of cortisol. Conditions that can damage the adrenal glands or pituitary gland include head injury, and some infections and autoimmune diseases.
  • A low level of cortisol can be caused by internal bleeding that could result in a shock. For example, if severe bleeding during childbirth is so bad that it damages the pituitary gland of the mother (Sheehan's syndrome) the levels of ACTH will decrease causing, evidently, a low level of cortisol.

Hypothyroidism may decrease cortisol levels. Drugs that may decrease levels include some steroid hormones.
Many factors are considered as influence in the concentration of cortisol. Those include heat, cold, infection, trauma, exercise, obesity, and debilitating disease. Pregnancy, physical and emotional stress, and illness are factors that help increase cortisol levels. Cortisol levels may also be high as a result of hyperthyroidism or obesity. A number of drugs can also boost cortisol levels, particularly birth control pills or other oral contraceptives, hydrocortisone (the synthetic form of cortisol), and spironolactone.

Salivary cortisol testing is being used more frequently to help diagnose Cushing syndrome and stress-related disorders but it requires specialized expertise to be processed accordingly.
Based on the National Institutes of Health studies, a normal value for a cortisol test done at 8 a.m. must rank from 6mcg to 23mcg per deciliter. Additionally, the National Institutes of Health admits that the normal value can vary, depending on which laboratory performed the analysis. Abnormal results from a cortisol level can indicate a disorder. Higher-than-normal cortisol levels may indicate an adrenal tumor, Cushing's syndrome or ectopic ACTH-producing tumors. Lower-than-normal cortisol levels are often and indicator of Addison's disease or hypopituitarism.
Once again, before having you test done have in mind that certain medications can alter the levels of cortisol in your blood. Estrogen and synthetic glucocorticoids, such as prednisone and prednisolone, can increase cortisol blood test results too. Besides, androgen and phenytoin can lower cortisol levels. Finally, the American Association for Clinical Chemistry has concluded that pregnancy, physical and emotional stress and other minor illnesses can also increase cortisol levels.



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