Nasal polyps are soft, painless, noncancerous growths that develop in the lining of the nasal passages or sinuses. They usually occur due to long-term inflammation caused by allergies, asthma, infections, or immune disorders. Small nasal polyps may not cause symptoms, but larger polyps can block nasal passages, leading to breathing difficulties, sinus infections, and a reduced sense of smell. Proper diagnosis and treatment can help manage symptoms and improve nasal breathing.