Authored by La Jolla Vitality Co. Gray hair and hair thinning are among the most common signs of aging, but they don't always occur solely because of age. Genetics, nutrition, hormones, stress, certain medical conditions, medications, and lifestyle habits can all influence the health of your hair. The good news is that while most age-related gray hair cannot currently be reversed, many causes of thinning hair are treatable, and some cases of premature graying caused by underl