Posted October 2, 2022 by Anusha ‐ 3 min read
A cortisol test measures the level of cortisol in your body. Cortisol, known as the stress hormone, is important to several bodily functions. Cortisol testing requires a sample of blood, urine, saliva or a combination, and the test often is repeated.
What is Cortisol?
Cortisol is a hormone made by the adrenal glands. It’s nicknamed the stress hormone because it helps you respond to stress. It also helps you:
Maintain blood pressure.
Regulate blood sugar and metabolism (how your body processes food to create energy).
What is a Cortisol test?
A cortisol test measures the level of cortisol in your body. Cortisol is a hormone made by your adrenal glands.
The test determines whether you have too much or too little of the hormone.
The test requires a sample of blood, urine, saliva or a combination. The results can help healthcare providers diagnose:
Addison’s disease, also known as hypocortisolism or primary adrenal insufficiency. This condition happens when your body has too little cortisol.
Cushing’s syndrome, also called hypercortisolism. The condition occurs when your body has too much cortisol.
Tumor affecting the production of cortisol. Various tumors may cause high cortisol levels.
How does a Cortisol test work?
Cortisol can be measured in the blood, urine, saliva or a combination. Your healthcare provider will tell you which test they recommend for you.
Blood test: In an office, clinic or lab, a healthcare provider inserts a thin needle into a vein in your arm. The needle collects a small sample of blood into a tube. You might feel a slight sting when the needle goes in.
Saliva test: You or a healthcare provider puts a swab in your mouth and waits a few minutes until the swab is saturated with spit. If you do the test yourself at home, your healthcare provider will give you a special kit. They’ll tell you what time to perform the test and how to return the sample.
Urine test: Your healthcare provider gives you a container to collect your pee. Most urinary cortisol tests collect all the pee you produce in 24 hours. Your healthcare provider may ask you to store the urine in a cold place, then return it to their office or a lab.
You may need to repeat cortisol testing twice in one day or multiple times over several days because cortisol levels vary.
How to prepare for a Cortisol test?
Your healthcare provider will give you specific instructions. For example, you shouldn’t eat, drink or brush your teeth before a salivary test. You may need to rest beforehand so that stress doesn’t interfere with the results.
What do Cortisol test results mean?
The outcome of cortisol testing can indicate several different things. Your healthcare provider will explain your results and what they mean.
High levels of cortisol might indicate
Effects of large amounts of certain medications.
Tumor in your pituitary gland that’s producing adrenocorticotropic hormone (ACTH), which stimulates the production of cortisol.
Tumor in your adrenal gland that’s producing too much cortisol.
Tumor elsewhere in your body, such as small cell lung cancer.
Low levels of cortisol might indicate
Tumor in your pituitary gland tumor that slows ACTH production.
Underactive or damaged adrenal glands.
Underactive pituitary gland.