Gray hair may be caused by aging, no special treatment is needed, or it may be caused by vitiligo and other diseases, you need to take medication and other treatments for the specific cause to turn black hair. 1. aging: with age, melanocyte function obviously decreases, so it will cause the hair to become white. Generally no special treatment is needed, if you think it affects the aesthetic appearance, you can dye your hair. 2. Vitiligo: common symptoms include white skin patches and white hair. Patients need to follow the doctor’s instructions to use topical glucocorticoids such as fluticasone propionate and mometasone furoate, calcium-modulated phosphatase inhibitors such as tacrolimus ointment and pimecrolimus cream, as well as vitamin D₃ derivatives such as carbotriol ointment and tacalcitol ointment. Secondly, phototherapy, decoloration therapy, and masking therapy are also available. There are many causes of gray hair, if you rule out that it is a physiological phenomenon, you should go to the hospital in time to treat the original disease.