The following hazards will be caused by going to bed at night before the hair is dry: 1, it will cause symptoms such as cold, because the hair is not dry, in the process of evaporation of water will take away a lot of heat, which will lead to a cold head, cold, so it is very easy to cause a cold, after the cold patients often appear headache, weakness and other uncomfortable symptoms. 2, sleep at night after washing the hair is not dry will cause vascular neurological headache, because the head is put cold will lead to cerebral artery spasm, fine cerebral artery spasm after the local blood supply is insufficient and cause neurological headache. The head put cold will lead to cerebral artery spasm, small cerebral artery spasm will appear after the local blood supply is insufficient and cause neurological headache, this situation can also be through physical therapy, massage and take ZhenBing and other traditional Chinese medicine treatment, has a very good effect. 3, the night hair is not dry early to bed can also cause rheumatic diseases, many people will appear to see the phenomenon of wind headache, this situation can use ibuprofen and other treatment, has a certain effect. There is a certain effect.