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).
Causes of Scalp tenderness that are uncommon. The following causes of Scalp tenderness are diseases or conditions that affect more than 200,000 people, but less than 1 million people in the USA: 1  Giant cell arteritis. 2  Herpes zoster. 3  Temporal arteritis-scalp tenderness.