Histologically, the adrenal glands are divided into adrenal cortex and adrenal medulla: 1. The adrenal cortex secretes salt corticosteroids, glucocorticoids and sex hormones, with salt corticosteroids mainly being aldosterone, glucocorticoids mainly being cortisol, and sex hormones mainly being androgens and a small amount of estrogen; 2. The adrenal medulla mainly secretes epinephrine and norepinephrine. These hormones are very important for the maintenance of normal vital signs in human body, as well as stress response and sexual function. Therefore, if there is a tumor or hyperplastic disease in the adrenal cortex or medulla, it will cause abnormal secretion of these hormones, which will lead to a series of diseases. Increased secretion of aldosterone can cause aldosteronism, increased secretion of cortisol can cause cortisolism, and increased secretion of adrenaline or norepinephrine can occur in pheochromocytoma.