One of the main causes of sinus drainage is simply being alive. Every day the human body produces several liters of sinus fluid and mucus, and all of that natural liquid must go somewhere.
It is a area of tenderness of the scalp in which people also sometimes feel stabbing headaches. Others just feel very sore and tender to the touch. It is felt to be caused by irritation of the connective tissue which attaches the muscles of the scalp to the skull (cranium).
Scalp massage can also help stimulate hair follicles and increase blood flow and circulation to the scalp -- ideal conditions for healthier-looking hair in any color. Avoid overt heat styling, perming, hair accessories, or any other rough treatment on gray hair, as it is drier than most hair.