What is a sinus headache?
If the linings of the ducts or tubes that connect the sinuses to the back of the nose become inflamed, the sinuses may not be able to drain normally, and pressure may build up within the blocked sinus. There may also be associated swelling and inflammation of the lining of the sinuses, resulting in increased mucus and fluid secretion. This increase in fluid combined with the inability to drain increases pressure within the sinus cavity, causing the pain of a sinus headache. The term sinusitis is used to describe inflammation of the sinus.