Sinusitis can cause facial pressure, sinus headache, and other symptoms. Treatment may depend on the cause.
A sinus infection, also known as sinusitis or rhinosinusitis, occurs when your nasal cities become swollen and inflamed. Fluid buildup in the sinuses can allow germs to grow, leading to a sinus infection.
Sinusitis is usually caused by a virus and often lasts even after other upper respiratory symptoms are gone. In some cases, bacteria — or, rarely, fungi — may cause a sinus infection.