In this case, the source of ACTH is suddenly removed, and replacement hormone must be taken until normal ACTH and cortisol production resumes. This can result from tumors or infections of the area, loss of blood flow to the pituitary, radiation for the treatment of pituitary tumors, or surgical removal of parts of the hypothalamus or the pituitary gland during neurosurgery of these areas. The symptoms of adrenal insufficiency usually begin gradually. Chronic, worsening fatigue and muscle weakness, loss of appetite, and weight loss are characteristic of the disease. Nausea, vomiting, and diarrhea occur in about 50 percent of cases.
Blood pressure is low and falls further when standing, causing dizziness or fainting.
Skin changes also are common in Addison's disease, with areas of hyperpigmentation, or dark tanning, covering exposed and nonexposed parts of the body. Addison's disease can cause irritability and depression. Because of salt loss, craving of salty foods also is common. Hypoglycemia, or low blood sugar, is more severe in children than in adults. In women, menstrual periods may become irregular or stop.