The sudden onset of sweating and lack of energy is mainly due to plant nerve dysfunction, which occurs when the sympathetic nerves are overexcited. For example, under strong stimulation, the sympathetic nerves of the patient will be excited, the blood vessels and muscles of the whole body will contract, and the sweat glands will secrete vigorously people will sweat. After the sympathetic excitement, due to the violent contraction of the muscles and blood vessels of the whole body, which is equivalent to strenuous exercise, people will feel especially weak and have no energy. If this happens, generally there is a strong stimulus, through their own regulation will slowly return to normal, if this happens without any trigger, it is certainly pathological, may be a problem in a body system. It is best to conduct a comprehensive examination, if there is no problem can be treated with symptomatic support with drugs that regulate nerves.