Nasal polyps are a non-cancerous mass of tissue inside the nose. The nose is lined with a layer of tissue called mucosa, and nasal polyps occur when this tissue becomes inflamed due to a variety of illnesses. Nasal polyps can be caused by allergies, asthma, allergic rhinitis, cystic fibrosis and other disorders of the nose and sinuses.
Depending on the exact location and size of the polyp), they can sometimes interfere with breathing. Symptoms of nasal polyps include difficulty breathing, congestion, and a runny nose (rhinitis). Doctors can usually see nasal polyps when doing an exam with an endoscope. Your physician may choose to try and shrink the size of the polyp with medications called steroids or surgically remove them. Even with surgery nasal polyps tend to recur in people prone to developing them.
University of Maryland Medical Center. Nasal Polyps - An Overview. Accessed April 28, 2009 from http://www.umm.edu/ency/article/001641.htm