What is the reason of grey hair?
Genetic or illness factors
Gray hair's appearance has a hereditary basis. People with gray or white hair before reaching old age frequently have a family history of autosomal dominant inheritance. It is also present in several syndromes (e.g., progeria syndrome, combined myotonic dystrophy). Gray hair may also emerge if you have significant conditions such pernicious anemia, hyperthyroidism, cardiovascular disease, TB, typhoid fever, or syphilis.
Mental factors
If a person is depressed for an extended period of time, in a foul mood, stressed out, or overworked, his hair may become white. For example, during our country's Spring and Autumn Periods, as well as the Warring States Period, Wu Zixu, a doctor from the State of Wu, dyed his entire head of hair black overnight to pass through the Zhaoguan Pass. Another example is Obama's hair, which was previously black, but after becoming president during the campaign, it went black. It becomes gray and white. It is easy to notice that the occurrence of white hair is linked to a person's mental health and psychological stress.
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