The adrenal gland produce hormones that affect various functions in the body. Some of these hormones are cortisol, aldosterone and androgens such as testosterone. When the adrenal glands are underactive or in a state of hypofunction, they produce low amounts of these hormones. Adrenal hypofunction, also called adrenal insufficiency, is caused by several conditions including autoimmune disease. Treatment for adrenal hypofunction is available once its symptoms are correctly recognized.
In primary adrenal insufficiency—also called Addison's disease—the underactivity of the adrenal glands results in low levels of the adrenal hormones cortisol and aldosterone. When adrenal insufficiency occurs as a result of pituitary issues, it is called secondary adrenal insufficiency. If problems with the adrenal glands cause this problem. The National Endocrine and Metabolic Diseases Information Service reports that Addison's disease affects 1 to 4 of every 100,000 individuals regardless of age or sex.
Cortisol is one of the hormones that becomes deficient in adrenal hypofunction One of its functions is maintenance of the heart and blood vessels in the cardiovascular system. It also regulates blood pressure and the immune system's inflammatory response. In addition, cortisol controls the amount of glucose in the blood. Aldosterone regulates blood pressure and the body's water and salt balance by regulating the amount of sodium retained in the body and how much potassium the body removes.
Disruption of hormonal function in adrenal hypofunction results in symptoms such as low blood pressure, low blood sugar, sweating and craving for salty foods. Other common symptoms of adrenal hypofunction include fatigue that keeps getting worse, weight loss, muscle weakness, loss of appetite, headache and irregular or no periods in women.
Adrenal hypofunction has more than one cause. A problem with the pituitary gland—a hormone-producing gland in the brain—such as insufficient blood supply or a pituitary tumor can cause secondary adrenal insufficiency. The pituitary gland produces corticotropin, a hormone that controls cortisol production. This hormone stimulates the adrenal glands to produce cortisol. If the pituitary gland is unable to produce enough corticotropin, cortisol production by the adrenal glands drops owing to lack of adequate stimulation.
An autoimmune response can also cause adrenal hypofunction. When the body's immune system attacks the adrenal glands, primary adrenal insufficiency or Addison's disease can also occur. Disease processes can also lower the activity of the adrenal glands. According to the Merck Manual Home Edition, 30 percent of Addison's disease cases are caused by destruction of the adrenal glands by infections such as tuberculosis, cancer and other diseases.
Doctors use several tests to diagnose adrenal insufficiency. Blood tests check the levels of cortisol, corticotropin, sodium and potassium in the body to help determine whether the disease is present. An adrenocorticotropic hormone stimulation test is can also aid in diagnosis. It involves administration of synthetic corticotropin also known as ACTH. Doctors measure cortisol levels before and after the test. Patients with adrenal insufficiency may show limited to no change in their cortisol levels. The adrenal glands and other areas in the body may also be visualized with imaging technology such as a computerized tomography, which shows abnormalities that could cause adrenal hypofunction.
Treatment of adrenal hypofunction or the resulting adrenal insufficiency involves replacing deficient adrenal hormones with synthetic ones. Hydrocortisone is a medication that doctors use to replace cortisol, whereas fludrocortisone is used to replace aldosterone.