Cortisol, Saliva

What is Cortisol?

Cortisol is a hormone produced by the cortex of the adrenal gland. It plays many important functions in our system, such as in the metabolism of lipids, proteins and carbohydrates, maintaining blood pressure, stabilizing blood glucose levels, and regulating our immune system. Cortisol is also responsible for the fight or flight response. It suppresses the functions that are not necessary t o a certain stressful response. The result will be a rapid heart rate, dry mouth, upset stomach, diarrhea and panic. Being the main hormone that regulates the best, and once a certain threat or danger is perceived, cortisol suppresses your growth process, your digestive system, your reproductive system, and how your immune system is responding.

The adrenal glands are two triangular-shaped glands found on top of the kidneys. Both the hypothalamus and pituitary gland control how much cortisol the adrenal glands are producing. When the level of cortisol in your blood go down, the hypothalamus in the brain releases corticotropin releasing hormones. These latter order the pituitary gland to produce adrenocorticotropic hormones (ACTH) that stimulate the adrenal gland and lead to the production of cortisol. For the cortisol to be regulated in our body, the hypothalamus, the pituitary, and adrenal glands have to be functioning properly.

Cortisol is found in two forms in our body. It is either bound to a blood protein and this constitute the majority of the cortisol; or, it is free and biologically active. When you test cortisol in the blood, you take a measure of the bound cortisol. When you test cortisol in the urine or saliva, you are testing the percentage of cortisol that is free. Whether you are measuring cortisol levels in the saliva, blood or urine, levels will descend throughout the day. They are the highest when you wake up and start decreasing as the day passes by. These peaks and declines will be different for a person who is working night shifts. Some conditions and illnesses may also disrupt cortisol levels.

According to a study published by the Garvan Institute of Medical Research in Australia, salivary cortisol levels are the best appropriate measure to assess the clinical functions of the adrenal glands. These levels of cortisol were found to be highly reflective to the serum cortisol levels.

There are many advantages to measuring cortisol levels in the saliva. It is a stress-free method that is non-invasive, allowing you to collect the necessary sample to assess the biological active steroid concentration. Salivary cortisol is correlated to the serum free cortisol levels. Using the saliva for cortisol testing usually consists inserting a swab into the mouth and making it saturated with saliva.

Why take the Cortisol, Saliva test?

The cortisol saliva test is used to diagnose some illnesses that are related to the malfunctions of the adrenal and pituitary glands. These include Addison’s disease and Cushing’s disease that play a role in how much cortisol is being produced in the body. Testing cortisol levels makes sure its levels are within normal range, which is necessary for the proper functioning of the stress responses, immune system, nervous system, circulatory system, skeletal system and metabolism.

If you have symptoms of low or high cortisol levels, you need to get tested. High cortisol levels are exacerbated in symptoms like hypertension, glucose, obesity, fragile skin, abdominal obesity, purple streaks on the abdomen, muscle wasting and osteoporosis. Low levels of cortisol are suggested when you are losing weight for no reason, you are feeling muscle weakness, feeling tired all the time, as well as having abdominal pain and low blood pressure. Some experience dark patches on the skin, which are suggestive of Addison’s disease and not secondary adrenal insufficiency. Cortisol testing can also monitor how effective the chosen treatment is. If findings are abnormal, further testing need to be done, such as stimulation and suppression testing.

What can cause abnormal levels of Cortisol, Saliva?

Many factors can affect the levels of cortisol in the body. Pregnant women and those taking exogenous estrogens, for instance, tend to have increased cortisol levels. Levels are also abnormal after hospitalization and surgery, as well as due to alcoholism, depression, exogenous glucocorticoids, and anticonvulsants. Phenytoin and androgens can lead to lower than normal levels of cortisol. Physical and emotional stress can lead to increased levels of ACTH, which causes abnormal levels of cortisol.

What your Cortisol, Saliva results mean?

The normal values of cortisol in saliva depends on the time of taking the test. For example, if the test was done between 7 am and 9 am, results should be between 100 and 750 ng/dL. If the test was done between 3 pm and 5 pm, results have to be less than 401 ng/dL, while they need to be less than 100 ng/dL if the saliva sample was taken between 11 pm and midnight.

High salivary cortisol levels are a characteristic of the Cushing syndrome. Someone with this diagnosis will have high cortisol levels from the morning until bedtime. The excess levels of the hormone are caused by an abnormally high production of ACTH by the pituitary glands, a tumor outside the pituitary, or by malfunctions of the adrenal glands. Low levels of cortisol reflect malfunctions in the adrenal glands (primary or secondary insufficiencies).

Once the abnormality is identified, you will be required to sit for additional tests like MRI or CT scans to evaluate the extend of damage to the glands.

Where can I get a Cortisol, Saliva test near me?

Please use our Lab Locator to find find a convenient testing location.

Reviewed By: Dr. Kurt Kloss, MD
Last Reviewed Date: Mar 12, 2020