ADRENAL GLAND
Adrenocortical insufficiency (Addison's disease) is the result of adrenal atrophy due to autoimmune disease or partial destruction by diseases such as tuberculosis or cancer. A progressive loss of aldosterone (mineralocorticoid) and cortisol (glucocorticoid) production leads to muscle weakness and fatigue, hyperpigmentation of the skin, low blood pressure, and weight loss, often with nausea and diarrhea.
The adrenal normally secretes sex hormones that exert minor effects on reproductive function; however, some congenital enzyme deficiencies lead to a marked overproduction of adrenal androgens. The resulting adrenogenital syndrome is characterized by viralization in the female, often with the development of male-type external genitalia.
Cushing's syndrome is similar to Cushing's disease, with the same symptoms. However, Cushing's syndrome is caused by the administration of large amounts of exogenous hormones or excess secretion of pituitary€TH, while Cushing's disease is caused by an ACTH-secreting tumor in the pituitary.
Excess mineralocorticoid secretion leads to a marked potassium depletion and to retention of excess body sodium. Symptoms include muscle weakness, hypertension, excess urine volume, and alkalosis due to the potassium loss. This is the clinical picture of Conn's syndrome, which is usually caused by an aldosterone-producing adrenal tumor.
The hypersecretion of epinephrine or norepinephrine from adrenal medullary tumors (pheochromocytomas) often results in severe hypertension. Patients may exhibit severe headaches, palpitations, chest pains, extreme anxiety, cold perspiration, skin pallor, and blurred vision.