Cortisol is a vital hormone that is produced by the adrenal glands, which are located above the kidneys. It is known as the "stress hormone", as it triggers many mechanisms in the body as a response to stressful situations. it also has other important functions such as regulating metabolism, reducing inflammation and contributing to immune functioning of the immune system.
Cortisol levels in the blood vary throughout the day. They begin to rise around 3 to 4 am and reaching their highest levels around 9 am. From then on, cortisol levels decreases, until it reaches its lowest levels around 11 pm.
High cortisol levels, or Cushing's syndrome, can occur due to excessive cortisol production, tumors or diseases, or due to prolonged use of corticosteroids. condition known as Cushing's syndrome. Low cortisol levels can be a sign of adrenal insufficiency and is caused by diseases in the adrenal glands, pituitary gland or hypothalamus.
How to test cortisol levels
Cortisol levels can be tested through a blood, urine or saliva sample. These tests are usually is indicated when there is a suspicion of Cushing's syndrome or adrenal insufficiency. Learn more about the cortisol test and how to prepare for it.
When low cortisol levels are suspected, the specimen is generally collected in the morning, between 8 and 9 am, when levels are expected to be at theri highest. Levels below 5 µg/dL may be a sign of adrenal insufficiency, while levels above 18 µg/dL will generally rule out this condition.
When high cortisol levels, or Cushing's syndrome, are suspected, the specimen should be collected after ingesting 1 mg of dexamethasone the night before, or by measuring it in saliva or urine.
Symptoms of high cortisol
High cortisol can cause signs and symptoms such as:
- Weight gain
- Weakness
- High blood pressure
- Rounded face
- Easy bruising
- Depression or emotional instability
- Pimples and increased hair growth
- Changes in menstruation
- Weakening of bones
These symptoms combined with high cortisol levels are signs of Cushing's syndrome, which is more common in people who use prolonged and high doses of corticosteroids. It is more likely to develop in those who are treating lupus, rheumatoid arthritis or asthma.
Read more about high cortisol levels and what can cause them.
Treatment for high cortisol
Treatment for high cortisol should always be guided by an endocrinologist, and will vary depending on the underlying cause. However, in most cases, surgical intervention is required.
Symptoms of low cortisol
The main symptoms of low cortisol are:
- General malaise
- Weakness
- Nausea and vomiting
- Abdominal pain
- Low blood pressure
- Low blood sugar levels
- Weight loss
Low cortisol levels in the body are associated with adrenal insufficiency, which can arise when there are diseases or abnormalities in the adrenal glands, pituitary gland or hypothalamus.
Treatment for low cortisol
Treatment for low cortisol should be guided by an endocrinologist, but is usually done with glucocorticoids and, in some cases, mineralocorticoids.