Headache symptoms after washing hair, may be due to cold water stimulation resulting in vasospasm, infection, cerebrovascular disease and other reasons. 1. Vasospasm: If the water temperature is too low or too high when washing hair, it will cause a short period of time scalp capillary spasm or diastole, and at the same time, it will stimulate the local muscle contraction, causing a headache, usually in the heat preservation, blow-drying hair will be relieved. 2. Upper respiratory tract infections: hair washing, especially after washing cold water, if not dried in time, may lead to viruses and other infectious diseases, in addition to headache may also appear fever, cough and other symptoms. 3. Cerebrovascular disease: changes in body position during shampooing and hot and cold stimuli may cause short-term fluctuations in blood pressure and vascular spasm, which may lead to aneurysm rupture and other serious cerebrovascular accidents, which may cause severe headache, vomiting, impaired consciousness and other symptoms, and require immediate medical attention. For people at high risk of cerebrovascular events, it is recommended to choose a warm environment when washing hair and pay attention to the water temperature. If headache symptoms are relieved within a short period of time, treatment is usually not necessary. If headache symptoms continue to be unrelieved or are more severe, or symptoms such as fever and cough occur, it is recommended to go to the hospital in a timely manner.