Nasal polyps are soft, painless, noncancerous growths that form on the lining of the nose or sinuses. They are often shaped like teardrops and can form in groups. Nasal polyps are associated with chronic rhinosinusitis, which is inflammation of the nasal passages and sinuses lasting 12 weeks or more. They can occur in anyone, but are more common in young and middle-aged adults.

Small nasal polyps might not cause symptoms, but larger growths or groups of nasal polyps can block the nose, leading to breathing problems, loss of smell, and infections. Common symptoms of chronic sinusitis with nasal polyps include runny nose, stuffiness, facial pain or pressure, and reduced sense of smell or taste.

The exact cause of nasal polyps is not fully understood, but research suggests that they develop due to inflammation of the nasal passages and sinuses. Allergies and infections are believed to cause the inflammation, and tissue taken from nasal polyps has been found to contain extra eosinophils, white blood cells linked to infections and allergic reactions.

Medication, such as nasal corticosteroid sprays, can often shrink or remove nasal polyps. Oral corticosteroids may also be used. If medication is not effective, endoscopic surgery may be required to remove the polyps. Sinus surgery to remove polyps is an option if nasal polyps are bothersome despite oral and/or corticosteroid sprays, but polyps often recur despite treatment.