The graying of hair on the right side of the forehead may be caused by aging, mottled disease and other factors. 1. Age: As the human body grows older, the function of melanocytes will slowly decay, resulting in hair gradually turning white, so the right forehead hair turns white. 2. Pemphigus: Pemphigus is a hereditary disease that mainly manifests itself as a triangular or diamond-shaped white spot on the forehead, accompanied by clusters of white hair on the forehead. The right forehead hair white may also have other reasons, it is recommended to go to the hospital in a timely manner to improve the examination, clear cause to give targeted treatment.