Benign growth inside nasal passage.Encyclopedia Entry for Nasal Polyp :Nasal polyps. Nasal polyps can grow anywhere on the lining of the nose or the sinuses. They often grow where the sinuses open into the nasal cavity. Small polyps may not cause any problems. Large polyps can block your sinuses or nasal airway. Nasal polyps are not cancer. They seem to grow due to long-term swelling and irritation in the nose from allergies, asthma, or infection. No one knows exactly why some people get nasal polyps. If you have any of the following conditions, you may be more likely to get nasal polyps: Aspirin sensitivity Asthma Long-term (chronic) sinus infections Cystic fibrosis Hay fever.If you have small polyps, you may not have any symptoms. If polyps block nasal passages, a sinus infection can develop. Symptoms include: Runny nose Stuffed up nose Sneezing Feeling like your nose is blocked Loss of smell Loss of taste Headache and pain if you also have a sinus infection With polyps, you may feel like you always have a head cold.Your health care provider will look in your nose. Polyps look like a grayish grape-shaped growth in the nasal cavity. You may have a CT scan of your sinuses. Polyps will appear as cloudy spots. Older polyps may have broken down some of the bone inside your sinuses.Medicines help relieve symptoms, but rarely get rid of nasal polyps. Nasal steroid sprays shrink polyps. They help clear blocked nasal passages and runny nose. Symptoms return if treatment is stopped. Corticosteroid pills or liquid may also shrink polyps, and can reduce swelling and nasal congestion. The effect lasts a few months in most cases. Allergy medicines can help prevent polyps from growing back. Antibiotics can treat a sinus infection caused by bacteria. They can't treat polyps or sinus infections caused by a virus. If medicines don't work, or you have very large polyps, you may need surgery to remove them. Endoscopic sinus surgery is often used to treat polyps. With this procedure, your doctor uses a thin, lighted tube with instruments at the end. The tube is inserted into your nasal passages and the doctor removes the polyps. Usually you can go home the same day. Sometimes, polyps come back, even after surgery.Removing polyps with surgery often makes it easier to breathe through your nose. Over time, however, nasal polyps often return. Loss of smell or taste does not always improve following treatment with medicine or surgery.Complications may include: Bleeding Infection Polyps coming back after treatment.Call your provider if you often find it hard to breathe through your nose.You can't prevent nasal polyps. However, nasal sprays, antihistamines, and allergy shots may help prevent polyps that block your airway. Newer treatments such as injection therapy with anti-IGE antibodies may help prevent polyps from coming back. Treating sinus infections right away also may help.Throat anatomy Throat anatomy Nasal polyps Nasal polyps.Bachert C, Calus L, Gevaert P. Rhinosinusitis and nasal polyps.