Nasal polyps are growths in the nasal cavity. They often look like grapes or small balloons within the structures of the nasal cavity.

What is going on in the body?
The nose acts as a filter, removing over 80% of particles in the air. A variety of agents entering the nose can cause inflammation. These agents include pollens, mold spores, animal dander, dust mites, dust, and dirt. Nasal polyps are the result of long-term, untreated nasal inflammation. Rarely, the polyps may protrude through the nostrils.

What are the causes and risks of the condition?
Many disorders can lead to nasal polyps, including:
- asthma, a disease of the airways that is the most common cause
- chronic allergies
- sinusitis, particularly sinus infections cause by a fungus
- cystic fibrosis, a congenital disease that affects the airways
- sensitivity to aspirin
- structural abnormalities of the nose