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
- Decreased or absent sense of smell
- Loss of sense of taste
- Facial pain or headache
- Pain in your upper teeth
- A sense of pressure over your forehead and face
When to see a doctor
See your doctor if your symptoms last more than 10 days. Symptoms of chronic sinusitis and nasal polyps are similar to those of many other conditions, including the common cold.
Seek immediate medical care or call 911 or your local emergency number if you experience:
- Serious trouble breathing
- Sudden worsening of your symptoms
- Double vision, reduced vision or limited ability to move your eyes
- Severe swelling around your eyes
- Increasingly severe headache accompanied by high fever or inability to tip your head forward
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).
Any condition that triggers chronic inflammation in your nasal passages or sinuses, such as infections or allergies, may increase your risk of developing nasal polyps. Conditions often associated with nasal polyps include:
- Asthma, a disease that causes overall airway inflammation and constriction
- Aspirin sensitivity may cause some people to be more likely to develop nasal polyps
- Allergic fungal sinusitis, an allergy to airborne fungi
- Cystic fibrosis, a genetic disorder that results in the production and secretion of abnormally thick, sticky fluids, including thick mucus from nasal and sinus membranes
- Churg-Strauss syndrome, a rare disease that causes the inflammation of blood vessels
Your family history also may play a role. There's some evidence that certain genetic variations associated with immune system function make you more likely to develop nasal polyps.
Nasal polyps can cause complications because they block normal airflow and fluid drainage, and also because of the chronic inflammation underlying their development. Potential complications include:
- Obstructive sleep apnea. In this potentially serious condition, you stop and start breathing frequently during sleep.
- Asthma flare-ups. Chronic rhinosinusitis can aggravate asthma.
- Sinus infections. Nasal polyps can make you more susceptible to sinus infections that recur often or become chronic.