Nasal polyps are soft, moist, fleshy growths which form in the lining of the nose and are thought to result from allergies or repeated infections. They are harmless, but if left untreated they can block both nostrils or press upon sensitive nerve endings. They are easily removed by surgery but tend to return. Anti-inflammatory nasal sprays can stop them returning in some cases. After surgery, most people comment on the ability to breathe through their noses again!