The lack of sweat on the face may be caused by physiological factors, such as the environment is wet and cold; it may also be caused by pathological factors, such as skin diseases, nerve damage, etc. It is recommended to go to the hospital for a clear diagnosis. 1. Physiological factors: Cold and wet environment: when the external environment is cold and wet, the body heat dissipation is reduced, and there is no need to dissipate heat by sweating a lot, so there will be a decrease in sweating on the face or the whole body. 2.Pathologic factors: (1) Skin diseases: such as local sweat gland metabolism abnormality, lack of sweat glands, etc., which can be manifested as generalized or limited anhydrosis; severe ichthyosis, scleroderma, leprosy, radiation dermatitis, etc., which can make the skin sweat glands destroyed or functionally impaired, and cause anhydrosis of the face. (2) Nerve damage: such as sympathetic nerve, medulla oblongata, cerebral bridge and other parts of the local damage, so that the nerve regulation is abnormal, which can cause facial or generalized anhydrosis. If it is caused by pathological factors, it is likely to cause other serious diseases due to the long-term sweat can not be discharged, so it is recommended that patients go to the regular hospital in time for examination, and according to the results of the examination of the symptomatic treatment.