Nasal polyps are soft, sac-like growths on the lining of the nose or sinuses.
Nasal polyps can grow anywhere on the lining of the nose or the sinuses. They often grow where the sinuses open into the nasal cavity. Small polyps may not cause any problems. Large polyps can block your sinuses or nasal airway.
Nasal polyps are not cancer. They seem to grow due to long-term swelling and irritation in the nose from allergies, asthma, or infection.
No one knows exactly why some people get nasal polyps. If you have any of the following conditions, you may be more likely to get nasal polyps: