What is cortisol?
Cortisol is the main stress hormone produced by your adrenal glands and is involved in the “fight or flight” response. It affects energy levels, blood pressure, digestion, and your sleep/wake cycle.
What does cortisol test for?
Chronic stress can lead to high cortisol levels and is known to affect heart health¹ and stress is known as a long-term risk factor for high blood pressure or hypertension². Abnormal levels of cortisol—either too high or too low—could indicate Cushing’s syndrome or Addison’s disease. Healthcare professionals may need to conduct additional tests to determine the cause of abnormal levels of cortisol.
The cortisol test measures whether your cortisol levels are high or low, which may be a sign of an adrenal gland condition or that lifestyle changes need to be made.
When should I test my cortisol levels?
You should test cortisol levels if you have symptoms of either low or high cortisol. High levels can affect your heart rate and energy levels.
Symptoms of Addison’s disease (low cortisol) include extreme fatigue, weight loss, darkening of the skin, low blood pressure (which may cause fainting), and more³. Levels of ACTH, the hormone that stimulates the production of cortisol, can be either elevated or decreased, depending on the cause of low cortisol⁴. Other tests may be needed to diagnose this disease.
Symptoms of Cushing syndrome (high cortisol) include obesity, high blood pressure, and elevated blood glucose levels⁴.
What is a normal cortisol level?
Reference values vary according to the time of day the test is taken and may vary between labs. Normally, they are highest in the early morning and decrease in the evening.
- 8:00 AM, 5–23 µg/dL
- 4:00 PM, 3–16 µg/dL⁶
A person’s normal levels of cortisol can be elevated by acute stress, alcoholism, depression, prescription drugs, pregnancy, and estrogen therapy⁴.
What does a low level of cortisol mean?
Lower than normal levels of cortisol could be indicative of Addison’s disease, hypopituitarism, or adrenal insufficiency⁴.
What does a high level of cortisol mean?
The most common cause of elevated cortisol levels in women is a high level of estrogen in the blood due to pregnancy or estrogen therapy⁴. Excess levels of cortisol can also be indicative of Cushing syndrome, which is a rare disorder. The most common cause of Cushing syndrome is the use of corticosteroids⁵, though it can also be caused by overproduction of the hormone ACTH.
How can I lower my cortisol levels?
Cortisol levels may be lowered by changing the medications you’re taking in consultation with your healthcare professional. If chronic stress is the cause of elevated cortisol, you may benefit from getting adequate sleep, exercising regularly, eating a healthy diet, and reducing the amount of caffeine you drink.