A person who is on long-term corticosteroid medication or has a pituitary tumor, adrenal hyperplasia, or adrenal tumor may suffer from symptoms of high cortisol. Normally, cortisol levels rise when the body is challenged by physical or psychological stress, infection, or any other event that strains the body’s resources. As a stress hormone, cortisol increases blood sugar; suppresses the immune system; and promotes metabolism of carbohydrates, fats, and proteins. Predictably, symptoms of high cortisol levels are secondary to these actions or are exaggerated sympathetic responses of the body to these elevations. Such symptoms include skin and hair changes, poorly controlled blood sugar, weight gain, high risk for infections, endocrine abnormalities, and increased heart rate and blood pressure.
The hypothalamus-pituitary-adrenal (HPA) axis controls the secretion of cortisol. As the hypothalamus secretes corticotropin-releasing hormone (CRH), the CRH in turn stimulates the pituitary gland to secrete the adrenocorticotropic hormone (ACTH). When ACTH is released to the blood, it is carried to the adrenal glands where it stimulates the cortex or outermost layer to produce cortisol.
High cortisol levels are present in the blood shortly after waking, in preparation for the stresses of the day. The lowest levels are present during the night, a few hours after bedtime, to promote relaxation. Any abnormality in the HPA axis, loss of the diurnal pattern of cortisol release, or intake of external sources of cortisol, such as hydrocortisone, can lead to symptoms of high cortisol and Cushing’s syndrome.
If a person has elevated cortisol levels for a long time, symptoms of cortisol excess become apparent. Common nonspecific symptoms, which are due to the over-activation of the sympathetic nervous system, include fatigue, weakness, increased thirst and urinary frequency, irritability, and depression. Another common symptom is weight gain due to increased fat and carbohydrate metabolism. Increased fat deposition often occurs in the abdomen, which makes a person prone to cardiovascular complications.
Insomnia often occurs as well, due to the disruption of the normal diurnal pattern of release. Additionally, a person with chronic high cortisol levels can suffer from high blood pressure and increased blood glucose, which increase the risk for heart attack and diabetes mellitus, respectively. The sympathetic nervous system is chronically activated as well. Therefore, lower sex drive could also be experienced.
Cushing’s syndrome is a disorder composed of a constellation of symptoms of high cortisol. Symptoms of Cushing’s syndrome include abdominal obesity, a round face or “moon face,” and “buffalo hump” or increased fat pads along the nape and upper back, despite having relatively thin arms and legs. The skin becomes thin and fragile, leading to easy bruising and poor wound healing. Unique to Cushing’s syndrome are skin manifestations called purple striae. These are purple-red, or violaceous, stretch marks that commonly occur on the abdomen as well as on the chest, face, neck, and thighs.
A woman with Cushing’s syndrome could experience hirsutism, or excessive hair growth, above the lips and along the midline of her body. She could also experience irregular menstruation. A man with Cushing’s syndrome could have diminished libido or erectile dysfunction. Therefore, people with high cortisol levels or Cushing’s syndrome often have difficulty conceiving or suffer from infertility.