Nasal polyps are soft, painless, noncancerous growths on the lining of your nasal passages or sinuses. They hang down like teardrops or grapes. They result from chronic inflammation due to asthma, recurring infection, allergies, drug sensitivity or certain immune disorders.
Small nasal polyps may not cause symptoms. Larger growths or groups of nasal polyps can block your nasal passages or lead to breathing problems, a lost sense of smell and frequent infections.
Nasal polyps can affect anyone, but they're more common in adults. Medications can often shrink or eliminate nasal polyps, but surgery is sometimes needed to remove them. Even after successful treatment, nasal polyps often return.
Symptoms
Nasal polyps are associated with inflammation of the lining of your nasal passages and sinuses that lasts more than 12 weeks (chronic rhinosinusitis, also known as chronic sinusitis). However, it's possible — and even somewhat more likely — to have chronic sinusitis without nasal polyps.
Nasal polyps themselves are soft and lack sensation, so if they're small you may not be aware you have them. Multiple growths or a large polyp may block your nasal passages and sinuses.
Common signs and symptoms of chronic sinusitis with nasal polyps include:
- A runny nose
- Persistent stuffiness
- Postnasal drip
- The decreased or absent sense of smell
- Loss of sense of taste
- Facial pain or a headache
- Pain in your upper teeth
- A sense of pressure over your forehead and face
- Snoring
Causes
Scientists don't yet fully understand what causes nasal polyps. It's not clear why some people develop chronic inflammation or why ongoing inflammation triggers polyp formation in some people and not in others. The inflammation occurs in the fluid-producing lining (mucous membrane) of your nose and sinuses. There's some evidence that people who develop polyps have a different immune system response and different chemical markers in their mucous membranes than do those who don't develop polyps.
Nasal polyps can form at any age, but they're most common in young and middle-aged adults. Nasal polyps may form anywhere in your sinuses or nasal passages, but they appear most often in an area where sinuses near your eyes, nose, and cheekbones all drain through winding passages into your nose (ostiomeatal complex).