The adrenal glands are located at the superior level of both kidneys, flush with the 8th thoracic vertebrae, and are orange in appearance. The left adrenal gland is half-moon shaped and the right adrenal gland is triangular cone shaped. Each adult adrenal gland is about 4 to 5 cm in length, 2 to 3 cm in width, and 0.3 to 0.6 cm in thickness. Each adrenal gland weighs about 4 to 5 g. The adrenal gland has a cortical layer and a medullary layer, with the cortical layer accounting for about 80% to 90% of the total weight of the adrenal gland. The outer layer is the globular zone, which accounts for about 15% of the cortex and secretes mainly salt corticosteroids, mainly aldosterone; the middle layer is the fasciculus, which accounts for about 78% of the cortex and secretes mainly glucocorticoids, mainly cortisol; the inner layer is the reticular zone, which accounts for about 9% of cortisol and secretes sex hormones, such as androgens, estrogens and progesterone. Glucocorticoids are necessary to maintain life and mainly regulate the metabolism of sugar, protein and fat, while salt corticoids mainly regulate the metabolism of electrolytes such as sodium and potassium. The main role of sex hormones is to promote hair, bone and muscle growth based on the development of secondary sex characteristics. The adrenal medulla is almost entirely composed of chromophores, brown in color, weighing about 1g, and mainly secretes epinephrine and norepinephrine, whose role is mainly to regulate the metabolism of sugar and fat as well as to strengthen cardiovascular contraction. Conn was the first to point out in 1955 that adrenocortical adenomas secreted too much aldosterone as the cause of the disease, hence the name Conn syndrome. This disease accounts for 1 to 2% of hospitalized hypertension cases and is a curable secondary hypertension. However, if the disease is prolonged, chronic hypertension and severe hypokalemia can also cause serious harm. Cushing’s syndrome, also known as cortisolism or Cushing’s syndrome, was first reported by Harvey Cushing, an American neurosurgeon, in 1921. The syndrome is a group of syndromes caused by the chronic overproduction of cortisol by the adrenal cortex due to various etiologies, mainly manifesting as full-moon face, polycythemia vera, centripetal obesity, acne, purple lines, hypertension, secondary diabetes and osteoporosis. Since long-term application of exogenous adrenal glucocorticoids or consumption of large amounts of alcoholic beverages can also cause clinical manifestations similar to Cushing’s syndrome, and all of them show hypercortisolism, so those caused by organic lesions are called endogenous Cushing’s syndrome; those caused by exogenous supplementation or alcohol are called exogenous, pharmacogenic or Cushing’s-like syndrome. Pheochromocytomas are mostly benign, accounting for about 90% of cases. Therefore, its shape is either smaller than a loquat or as large as a cantaloupe. Generally, it is the size of a mandarin and is flat and round with a slight fan shape, and the cut surface is dark yellow or brown. Pheochromocytoma is predominantly found in young adults aged 20 to 40 years old, with the ratio of men to women being almost equal. The main symptoms are hypertension and changes in basal metabolism. Pheochromocytoma should be surgically removed because it is mostly a benign tumor, and most of them have good postoperative results.