A cortisol test evaluates whether the cortisol level in the blood, urine, or saliva is normal. Cortisol is a hormone that impacts nearly every organ. It helps the body in the following ways:
- Reduce inflammation
- Respond to stress
- Control blood pressure
- Regulate blood sugar and metabolism
Cortisol is generated by the adrenal glands, which are two tiny glands found above the kidneys. The pituitary gland in the brain produces a hormone that instructs the adrenal glands on how much cortisol to produce. Cortisol levels that are abnormally high or low may indicate an adrenal gland condition, a pituitary gland problem, or a tumor that produces cortisol.
Increases in cortisol can also occur if you take large doses of certain steroid medications for an extended period of time. Low levels can also occur if someone abruptly discontinued the medication.
Other names: salivary cortisol, urinary cortisol, free cortisol, blood cortisol, plasma cortisol
What is it used for?
A cortisol test is used to assist in diagnosing medical disorders caused by an excess or deficiency of cortisol. These conditions include adrenal gland abnormalities such as:
- Cushing's syndrome is a disorder in which the body creates excessive levels of cortisol over time, resulting in various health issues.
- Addison's disease, on the other hand, is a disorder in which the adrenal glands do not produce enough cortisol due to damage or malfunction.
- Secondary adrenal insufficiency is a condition where the pituitary gland fails to stimulate the adrenal glands to produce enough cortisol, leading to low cortisol levels in the body.
Cortisol testing is also used to monitor the effectiveness of treatment for certain conditions.
What is the purpose of a cortisol test?
If you experience symptoms of an illness that impacts cortisol levels, you may need a cortisol test. Symptoms of Cushing's syndrome may include:
- Thin arms and legs
- Weight gain
- Wide purple streaks on the breasts, stomach, hips, and under the arms
- Round face
- Muscle weakness
- Easy bruising
Common Addison disease and adrenal insufficiency symptoms include:
How to prepare for the test?
The preparations will vary depending on the type of test. Make sure to follow all of the provider's instructions.
Because stress might increase cortisol levels, you may need to rest before the test. A blood test will need two appointments at various times of the day. Some medications may need to be discontinued prior to a saliva test. Inform the provider about all medications you use, including skin creams. Do not discontinue any medications without first consulting with the doctor.
What do the results mean?
A cortisol test alone cannot identify the cause of high cortisol levels. If the cortisol level is higher than normal, you will normally be subjected to additional tests to find the reason for the issue.
Cortisol levels that are too high may indicate Cushing's syndrome. It could be caused by:
- Long-term use of high doses of some steroid medications for disorders such as asthma, rheumatoid arthritis, and lupus.
- Tumors in the pituitary gland or other parts of the body that produce an excessive amount of the hormone that directs the adrenal glands to produce cortisol.
- Adrenal gland tumors that produce excessive cortisol
Low cortisol levels may indicate Addison's disease or secondary adrenal insufficiency:
- Addison's disease is commonly caused by adrenal gland damage caused by conditions such as:
- Certain infections, such as HIV/AIDS and tuberculosis (TB)
- Autoimmune diseases
- Common causes of secondary adrenal insufficiency include:
- Problems with the pituitary gland
- Autoimmune diseases
- Traumatic brain injury
The most prevalent reason for low cortisol levels is abruptly discontinuing steroid medications after a long period of treatment.
If the cortisol levels are higher than usual, it may not always indicate that you have a medical issue that requires treatment. Cortisol levels can be influenced by the following factors:
- Pregnancy
- Serious illness
- Obesity
- Certain medicines, such as birth control pills
- Certain thyroid diseases
- Stress
- Exercise
- Hot and cold temperatures
Talk to the physician to learn what the test results indicate.
