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 and hair root pain have many causes, the most common of which is pulling hair too tight, explains WebMD. Migraine headaches, head injuries and skin disorders may also induce scalp pain, according to Healthgrades. Other explanations include head lice and serious conditions, such as brain tumors and scalp wounds.