Sinus conditions that may cause pressure in the head include sinus blockage, a deviated septum, narrow sinuses, an extra sinus cavity and allergies, according to WebMD. Most people have eight sinus cavities, and when the cavities clog with mucus, pressure in the head is common.
Sinus blockage is one reason for pressure in the head, and this occurs when mucus backs up, explains WebMD. A deviated nasal septum is another reason for pressure in the head, and this occurs when the wall of cartilage and bone separates from the nasal passages. Approximately 80 percent of people have a nasal septum that displaces to one side, which means one nasal passage is smaller. Sinuses that are naturally narrow may also cause pressure in the head.
In about 10 percent of people, sinus pressure may occur due to an extra sinus cavity, which means the transition space is narrower than usual, states WebMD. There is also the possibility that sinus pressure occurs due to allergies or sensitivities to the environment. This sensitivity causes the blood vessels in the nose to dilate, which means the mucus cannot get through as easily, leading to pressure. A doctor can prescribe medications to control the symptoms, and people who have allergies or sinus issues should stay away from irritants such as chemical odors or tobacco smoke. These may make the pressure worse.