What is a cortisol test?
Cortisol is a hormone that affects almost every organ and tissue in your body. It plays an important role in helping you to:
- Respond to stress
- Fight infection
- Regulate blood sugar
- Maintain blood pressure
- Regulate metabolism, the process of how your body uses food and energy
Cortisol is made by your adrenal glands, two small glands located above the kidneys. A cortisol test measures the level of cortisol in your blood, urine, or saliva. Blood tests are the most common way of measuring cortisol. If your cortisol levels are too high or too low, it may mean you have a disorder of your adrenal glands. These disorders can be serious if not treated.
Other names: urinary cortisol, salivary cortisol, free cortisol, dexamethasone suppression test, DST, ACTH stimulation test, blood cortisol, plasma cortisol, plasma
What is it used for?
A cortisol test is used to help diagnose disorders of the adrenal gland. These include Cushing's syndrome, a condition that causes your body to make too much cortisol, and Addison disease, a condition in which your body doesn't make enough cortisol.
Why do I need a cortisol test?
You may need a cortisol test if you have symptoms of Cushing's syndrome or Addison disease.
Symptoms of Cushing's syndrome include:
- Obesity, especially in the torso
- High blood pressure
- High blood sugar
- Purple streaks on the stomach
- Skin that bruises easily
- Muscle weakness
- Women may have irregular menstrual periods and excess hair on the face
Symptoms of Addison disease include:
- Weight loss
- Fatigue
- Muscle weakness
- Abdominal pain
- Dark patches of skin
- Low blood pressure
- Nausea and vomiting
- Diarrhea
- Decreased body hair
You may also need a cortisol test if you have symptoms of an adrenal crisis, a life-threatening condition that can happen when your cortisol levels are extremely low. Symptoms of an adrenal crisis include:
- Very low blood pressure
- Severe vomiting
- Severe diarrhea
- Dehydration
- Sudden and severe pain in the abdomen, lower back, and legs
- Confusion
- Loss of consciousness