Low cortisol levels are characterized by values in the blood that are less than 5 µg/dL in the morning. It can cause symptoms such as fatigue, reduced appetite, weight loss and mood swings.

Cortisol is a hormone that is produced by the suprarenal glands. Low cortisol levels may be a sign of autoimmune dysfunction, infections, tumors, or suddenly discontinuing corticosteroid medications.

If you suspect you have low cortisol levels, it is important to consult your family doctor or an endocrinologist. Treatment for this finding depends on the underlying cause, and typically involve hormone replacement through medications such as prednisone or hydrocortisone.

Main symptoms

The main signs and symptoms of low cortisol levels are:

Fatigue
Lack of energy
Decreased appetite
Abdominal pain
Mood changes, such as irritability, depression and apathy
Drop in blood sugar levels
Low blood pressure
Weight loss

Adrenal gland disorders can also be referred to as Addison's disease. This condition can cause a drop in cortisol, as well as a drop in other hormones like aldosterone and androgen hormones.

Confirming a diagnosis

Low cortisol levels are usually diagnosed by an endocrinologist or family doctor, who will review blood test results and take the presenting symptoms into account.

The doctor may also order additional testing, such as bloodwork to check adrenocorticotropic hormone (ACTH) levels, sodium and potassium, or an MRI.

Common causes

The main causes of low cortisol are:

Sudden discontinuation of corticosteroid medications, especially when used for prolonged durations or in high doses
Autoimmune disorders
Use of medications, such as ketoconazole, fluconazole, carbamazepine and phenytoin
Infections, such as HIV, syphilis or cytomegalovirus
Illnesses like tuberculosis and leprosy
Surgical removal of adrenal glands, also known as adrenalectomy
Tumors or metastases, especially when they affect the pituitary or adrenal glands
Genetic causes

Furthermore bleeding that affects the adrenal glands from anticoagulants or clotting disorders can also lead to low cortisol levels.

Treatment options

The treatment of low cortisol levels can be done by replacing this hormone, using corticosteroid medications, such as prednisone or hydrocortisone, as prescribed by an endocrinologist.

In addition, the doctor may also recommend the replacement of other hormones produced by the adrenal glands, such as androgens and mineralocorticoids.

Depending on the cause of the low cortisol levels, treatment may also involve chemotherapy, radiation therapy and/or surgery, in the case of tumors. Low levels caused by autoimmune disease or infections can also be corrected through the treatment of these conditions.