Normal sweat secretion regulation center is located in the hypothalamus of the lower region, through the brainstem and the spinal tract after the termination of the lateral horn, and then through the sympathetic nerve postganglionic nerve fibers and regulate the body’s sweat. Thoracic sympathetic nerve center is located in the 2nd to 6th segment, its preganglionic fibers mainly in the T2, T3 sympathetic ganglion innervates the hand sweat glands, a few people from the T1 has a major branch innervates the hand; in addition, there are a small number of people from the T2, T3 directly through the Kuntz bundle to reach the upper limbs; axillary sweat glands are innervated by the T4, T5. Primary hyperhidrosis is mainly caused by abnormal hyperfunction of the thoracic sympathetic nerve. In addition to the sympathetic nerve, there are other factors: ① emotional factors such as anxiety, fear, embarrassment, anger, excitement and mental shock and other emotional factors. ② febrile diseases due to bacterial cell membranes or proteolytic products from the body degradation of the release of pyrogens so that the hypothalamus thermoregulatory center of the threshold increases resulting in increased body temperature and lead to sweating. Endocrine and metabolic diseases such as hyperthyroidism, diabetes mellitus, pheochromocytoma. ④ Cardiovascular diseases In heart failure, increased sweating is related to increased sympathetic nerve activity, and sweating is mainly seen in the head and neck, which is common in patients with myocardial ischemia or myocardial infarction. ⑤ Intrathoracic organisms or injuries Intrathoracic organisms or injuries can cause ipsilateral hyperhidrosis because of increased sympathetic activity of thoracic sympathetic nerves or postganglionic fibers as a result of increased pressure, and phytophysical neuropathy caused by diabetes mellitus. Excessive sweating is caused by olfactory stimulation. (vii) Compensatory hyperhidrosis Limiting hyperhidrosis can occur when there is no sweating in other parts of the body, which can be seen as a result of damage to the sympathetic nerves, damage to the spinal cord or sympathetic trunk, and phytoneuropathy due to diabetes mellitus.