Cortisol, a hormone normally secreted by the adrenal glands, has widespread and complicated effects on the metabolism of the body. It's also given as a medication to treat a wide range of diseases, including respiratory and neurological conditions. The most common cause of excessive cortisol is exogenous administration, that is, taking cortisol as a medication, at the prescribed dose. The symptoms of excessive cortisol are known as Cushing's syndrome.
Blood Sugar and Body Fat
Cortisol opposes insulin in its effect on sugar. While insulin helps tissues take in and absorb glucose, cortisol increases its amount in the blood. Excessive cortisol can lead to diabetes. It also alters the metabolism of fat and the distribution of fat in the body. The Cushingoid appearance includes a moon-shaped face, fat between the scapulas, known as a buffalo hump, and truncal obesity, or fat in the abdominal area. In contrast, the arms and legs are thin.
Bones and Connective Tissue
Cortisol affects the metabolism of bones. Osteoporosis in Cushing's syndrome occurs preferentially in the vertebral bones, causing back fractures even with minor trauma. Other bones, such as the long bones of the arms and legs, are less affected. Skin stretches and bruises easily. Wide purple striae, which are stretch marks in the abdomen, are common.
Psychiatric Effects
An excess of cortisol can lead to either depression or mania, most commonly the latter--an elevation of mood accompanied by little sleep, irritability, pressured speech and abnormally high energy level. Psychosis can also occur, meaning a detachment from reality, and it can be accompanied by hallucinations.
Other Symptoms
Excessive cortisol can cause high blood pressure. Weak muscles are common, as is general fatigue. Women can have excessive hair growth and disrupted menstrual cycles. Excessive thirst and fluid retention are common. Total body weight increases. The immune response can also be impaired in Cushing's, and wounds take longer to heal.
References
- "Harrison's Principles of Internal Medicine, 17th edition"; Anthony Fauci et al.; 2008
- Mayo Clinic: Cushing's Syndrome
