Sinusitis is a condition that occurs when the lining of the sinuses becomes inflamed, swollen, and/or infected. The sinuses are hollow cavities located in the bones around the nose, and they are connected to the nasal passages. When the sinuses become inflamed or infected, they can become blocked, and mucus can build up. This can cause pain and pressure in the face, nasal congestion, headache, and a runny nose.
There are several types of sinusitis, including acute sinusitis (which usually lasts less than four weeks), subacute sinusitis (which lasts four to 12 weeks), chronic sinusitis (which lasts more than 12 weeks), and recurrent sinusitis (which occurs several times a year).
Sinusitis is often caused by a viral or bacterial infection, but it can also be triggered by allergies, nasal polyps, or a deviated septum. Treatment for sinusitis depends on the underlying cause and may include antibiotics, decongestants, nasal steroids, saline nasal irrigation, or in some cases, surgery.