Sinusitis is a condition characterized by inflammation of the sinuses, which are air-filled cavities located around the nose, eyes, and forehead. This inflammation occurs when the lining of the sinuses becomes swollen, blocking normal drainage of mucus and creating an environment where germs can grow. Sinusitis may be caused by viral, bacterial, or fungal infections, as well as allergies, nasal polyps, or structural problems such as a deviated nasal septum.

Common symptoms of sinusitis include facial pain or pressure, nasal congestion, thick nasal discharge, headache, reduced sense of smell, cough, and fatigue. Some individuals may also experience fever, tooth pain, or a feeling of fullness in the ears. Sinusitis can be classified as acute, lasting up to four weeks; subacute, lasting four to twelve weeks; or chronic, persisting for more than twelve weeks despite treatment.

Diagnosis is usually based on symptoms, medical history, and physical examination. In some cases, imaging studies or nasal endoscopy may be used to confirm the condition. Treatment depends on the cause and severity of sinusitis. Acute viral sinusitis often improves with rest, fluids, and symptom-relieving medications, while bacterial sinusitis may require antibiotics. Nasal sprays, decongestants, and saline rinses are commonly used to reduce inflammation and improve drainage.

Chronic sinusitis may require long-term management, including allergy treatment or, in severe cases, surgery to improve sinus drainage. With appropriate treatment and preventive care, most people with sinusitis can achieve significant relief and maintain a good quality of life.