Nasal polyps are soft fleshy non-cancerous (benign) swellings that grow inside the nose. They may be yellowish, grey or pink in colour. The most common symptoms they cause are a stuffy, runny nose. Nasal Polyps are common and non-cancerous (benign) and can vary greatly in size. There may be only one nasal polyps but sometimes several grow like a small bunch of grapes on a stem.