Cortisol

What is Cortisol?

Cortisol is a steroid hormone that is formed by the adrenal glands. It is released into the bloodstream and transported all around the body. Cortisol is one of the glucocorticoids. It plays numerous roles depending on the cells it is heading towards. All cells in our body have receptors for cortisol. Among the numerous roles this hormone plays are controlling our blood glucose levels and regulating our metabolic rate, controlling our salt and water balance, regulating our blood pressure and memory, acting as an anti-inflammatory, as well as playing an important role in the formation of the fetus during pregnancy.

What is special about this hormone is that its levels in the blood, under normal circumstances, vary throughout the day. It is found in higher concentration in the morning when you wake up; and, starts decreasing with the day passing. If you are a person who is working at night, this pattern is reversed. From another angle, when you experience stress, your body starts creating more of this hormone to manage the bodies response so this new external trigger. Three parts of the body regulate the secretion of cortisol. These are the hypothalamus in the brain, the adrenal glands and the pituitary gland. These three pathways are called the hypothalamic-pituitary-adrenal axis.

When your blood levels of cortisol diminish, the hypothalamus releases corticotropin releasing hormones that trigger the release of adrenocorticotropic hormone from the pituitary gland into the bloodstream. When the adrenal gland detects the adrenocorticotropic hormone, it secretes cortisol, causing its levels to rise in the blood. The adrenal glands are endocrine glands that are also responsible for the secretion of adrenaline. They are located on top of the kidney and have an outer cortex and an inner medulla. The cortisol is produced by the cortex.

This cortisol test measures the levels of cortisol in your blood. The test is simple and indicates the level of cortisol at the time of the test. It is then compared to a reference range that is relative to the time of the test.

Why is the cortisol blood test ordered?

The cortisol levels test helps determine if you have Cushing syndrome, or a primary and secondary adrenal insufficiency that may lead to Addison disease. It also helps detect any condition that may sabotage the proper functioning of the pituitary and adrenal glands. If you think you may have symptoms of high or low cortisol levels, you need to get tested.

When you have higher levels of cortisol in your blood, with time it may develop into Cushing syndrome. Symptoms of high cortisol levels include gaining weight rapidly, especially in the face, chest and abdomen area while having thin arms and legs, having a flushed round face, starting to experience high blood pressure, and osteoporosis. Other signs include noticing bruises and purple stretch marks on your skin, having your muscles feeling weak, starting to have mood swings such as becoming highly irritable, anxious and depressed, and finally feeding thirsty all the time. Some also begin experiencing high frequency of urination. When your cortisol levels are high and remain undiagnosed and untreated, you may start noticing that your sex drive is decreasing and your night is becoming sleepless. Others, report impaired healing and cell repairing, menstrual problems, as well as a weakened mental function.

You also need to be tested if you are experiencing signs and symptoms that may be caused by low cortisol levels. These are usually linked to problems of the pituitary and adrenal glands. Signs include fatigue, dizziness especially when you stand up, weight loss, muscle weakness, experiencing more changes as well as having dark spots on your skin. Low levels of cortisol are linked to a condition called primary adrenal insufficiency. It is a rare auto-immune condition that damages the adrenal glands. It starts slowly; but, progresses into a very serious condition. Undiagnosed and untreated very low levels of cortisol can even be life threatening.

What affects the results of the cortisol blood test?

Cortisol levels in the blood may be affected by many factors. First, make sure your test is done in the morning as your cortisol levels are normally at their peak, during this time.

Second, eating before your test will not have any effect on the results.

Third, certain medications can affect the levels and sabotage your results. These include drugs that contain estrogen, as well as synthetic glucocorticoids such as prednisone. These two groups of drugs have a tendency to increase cortisol level. Pregnancy can have the same effect.

Cortisol levels can be decreased by drugs that contain androgens as well as phenytoin. Physical stress, emotional stress and illness affect levels as well. A study published by the British journal of psychiatry explains that 50% of those who have major depression tend to oversecrete cortisol.

What your Cortisol results mean?

This cortisol test is a blood test. Any blood sample taken between 8:00 am and 6:00 pm is expected to be around 23 mcg/dL. Since laboratories have different techniques to measure cortisol, normal ranges may vary slightly. If your levels are above normal; then, you may have a tumor or growth on your pituitary gland that is causing it to produce high levels of ACTH. High levels may also indicate having a tumor on the adrenal gland that is causing high formation of cortisol, or a tumor anywhere else in the body that may have an interference with cortisol production.

When your cortisol levels are lower than normal; this normally indicates that you either have Addison disease or Hypopituitarism. Addison’s disease is also referred to as primary adrenal insufficiency. It is a long-term disorder of the adrenal glands that no longer produce the right amounts of steroids in the body. Hypopituitarism is a condition where the pituitary gland fails to produce enough hormones. In children, this condition may lead to dwarfism, while in adults it could lead to premature aging.

Where can I get a Cortisol test near me?

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

Reviewed By: Dr. Kurt Kloss, MD
Last Reviewed Date: Feb 28, 2022