Chronic sinusitis is a long-lasting inflammation of the sinuses, which are the air-filled spaces located in the skull around the nose. This condition can cause symptoms such as nasal congestion, facial pain, and a reduced sense of smell. It often occurs when the sinus openings become blocked, leading to mucus buildup and potential infection. The causes of chronic sinusitis can vary and may include allergies, nasal polyps, or structural issues in the nasal passages. Treatment options often involve medications like nasal sprays or antibiotics, and in some cases, surgery may be necessary to improve sinus drainage and relieve symptoms.