The central regulator of normal sweat secretion is located in the inferior hypothalamus, which passes through the brainstem and spinal tract and terminates in the lateral horn, and then through the sympathetic postganglionic nerve fibers that regulate sweating in the body. The postganglionic transmitters are mainly acetylcholine and catecholamines. The thoracic sympathetic nerve center, which governs sweat secretion, is located in segments 2-6, and its preganglionic fibers innervate the hand sweat glands mainly in T2 and T3 sympathetic ganglia, with a few individuals having major branches from T1 to innervate the hand; a few others have direct access to the upper extremities via the Kuntz bundle from T2 and T3; the axillary sweat glands are innervated by T4 and T5 [2]. Primary hyperhidrosis is mainly caused by abnormal hyperfunction of the thoracic sympathetic nerve. Tu Yuanrong et al [3] observed the ultrastructure of the thoracic sympathetic nerve tissue in 23 patients with hand sweating by thoracoscopic resection and concluded that the increased number of myelinated nerve fibers and thickened myelin sheath of the thoracic sympathetic nerve is one of the causes of hyperhidrosis. In addition to sympathetic nerve, there are other factors: 1, emotional factors such as anxiety, fear, embarrassment, anger, excitement and mental shock. 2, febrile diseases due to bacterial membranes or proteolytic products released from the human body degradation of pyrogen to raise the threshold of the hypothalamus thermoregulatory center resulting in increased body temperature and sweating. 3, endocrine and metabolic diseases such as hyperthyroidism, because the body’s metabolism increases the sensitivity of the plant nerves to adrenaline increased. Diabetes, because of the poor control of blood glucose in diabetic patients, resulting in large fluctuations in blood glucose or long-term high blood glucose concentration, on the emergence of microangiopathy, resulting in diabetic neuropathy, sympathetic nerve postganglionic fibers cause sweat gland regulation dysfunction, and excessive sweating is mainly seen in the face and neck, diabetic patients sometimes due to hypoglycemia can also lead to excessive sweating; pheochromocytoma, this is adrenaline and norepinephrine This is the result of excessive secretion of adrenaline and noradrenaline, which leads to sweating. 4, cardiovascular disease In heart failure, increased sweating is associated with 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 proliferation or injury Intrathoracic proliferation or injury can cause ipsilateral hyperhidrosis as a result of increased sympathetic nerve activity in thoracic sympathetic nerves or postganglionic fibers due to increased pressure, and vegetative neuropathy caused by diabetes. 6, olfactory hyperhidrosis The stimulation of the sense of smell causes hyperhidrosis. 7, compensatory hyperhidrosis Limited hyperhidrosis can occur when there is no sweating in other parts of the body. This condition can be seen in sympathetic nerve injury (such as after thoracic sympathectomy), damage to the spinal cord or sympathetic nerve trunk, and phytonuropathy caused by diabetes mellitus.