Hyperhidrosis is a condition in which the sympathetic nerves are overexcited or highly stressed, causing excessive sweat secretion. Under normal circumstances, the sympathetic nerve regulates body temperature by controlling sweating and heat dissipation, but in patients with hyperhidrosis, sweating and facial flushing are completely out of control, leaving the patient in a state of helplessness, agitation or panic. The diagnosis of sweating caused by hyperhidrosis relies on the typical sweating manifestations, but also requires a combination of laboratory tests, imaging tests and autonomic function test results. Examination of high sympathetic nervousness: 1. Medical history The medical history should include detailed questions about the causes of abnormal sweating before it occurs. Such as whether there is mental tension, emotional excitement, whether there is neurotrauma, history of medication and disease. For example, hemophilia can cause hemosiderosis, and taking chlorpheniramine can cause redness of sweat. Ask if there are similar patients in your family to exclude genetic factors. 2.Physical examination Physical examination should focus on whether there are skin signs that induce abnormal sweating. If the patient is found to have ichthyosis, it is the cause of localized anhidrosis. The patchy damage of tuberculous leprosy, in addition to local sensory abnormalities, often has localized anhidrosis. Chronic radiodermatitis damage, in addition to dry skin, atrophy, capillary dilatation, often have localized anhidrosis. Therefore, a detailed physical examination can identify the cause of abnormal sweating to make a clear diagnosis. 3, laboratory tests Sympathetic hyperhidrosis caused by high nervous tension can be positive for hemoglobin. Sweating test: for local sweating dysfunction, apply tincture of iodine to the skin lesion, wait for dryness, inject 1:1000 concentration of Mao Guo Xiang Xiang Qi liquid 0.1-0.2ml respectively in the skin, gently aspirate the exudate from the tip, immediately sprinkle a thin layer of starch. 3-5min later, the normal skin starch appears blue dots, indicating normal sweating function. If there is no blue dot in the lesion, it means that the local sweating function is dysfunctional and no sweat is discharged.