It is not recommended to wash your hair after a meal, because a large amount of blood in your body will flow to the gastrointestinal tract after a meal, which often leads to insufficient blood flow to the brain, that is, insufficient blood supply to the corresponding blood vessels, so some people will have dizziness after a meal. From this point of view, it is better to wash your hair before eating.

For the elderly, especially those with cerebrovascular insufficiency, if they wash their hair after meals, they are prone to cerebral vasospasm, thus aggravating the symptoms of cerebrovascular insufficiency.