Nasal polyps are fleshy swellings that develop in the lining of the nose and paranasal sinuses, the air-filled spaces that are linked to the nasal cavity. They are non-cancerous growths.
Polyps vary in size; they may be yellowish-brown or pink and are shaped like teardrops. As they grow, they eventually look like grapes on a stem.
Polyps may grow in one or both nostrils at the same time; they can grow on their own or in clusters.
Large polyps or clusters can cause breathing difficulties and can affect the patient’s sense of smell. They may block the sinuses and cause problems, such as regular infections.
Nasal polyps affect an estimated 4-40 percent of the general population, and they seem to be 2-4 times more common in males than females. People who develop them tend to do so as young or middle-aged adults.
Individuals with asthma, frequent sinus infections, and allergies are more likely to develop them. Some children with cystic fibrosis may develop nasal polyps.
Fast facts on nasal polyps
Here are some key points about nasal polyps. More detail and supporting information is in the main article.
Nasal polyps are much more common in men than women
Often nasal polyps do not present any symptoms, making it difficult to know exactly how common they are
Sometimes, nasal polyps can cause sleep apnea
Nasal polyps can arise at any age
A constant runny nose may be a symptom of nasal polyps.
Individuals with nasal polyps tend to have chronic inflammation of the lining of the nasal passages and sinuses (chronic sinusitis).
If there are clusters or large polyps, the patient’s nasal passages and sinuses may be obstructed.
Some people with small nasal polyps may have no signs or symptoms; however, the following are common:
Runny nose – this may be chronic, with the patient feeling as if they always have a cold
Persistent stuffy or blocked nose – in some cases, the patient may find it hard to breathe through the nose, causing sleeping problems
Postnasal drip – a feeling of mucus continually running down the back of the throat
Either no sense of smell or poor sense of smell – this may not improve after polyps are treated
Poor sense of taste – this may not improve after polyps are treated
Pain in the face
Itchiness around the eyes
Obstructive sleep apnea (in severe cases) – this is a potentially serious condition where the patient stops breathing during sleep
Double vision (in severe cases) – more likely to occur if the patient has allergic fungal sinusitis or cystic fibrosis
Risk factors include:
Sensitivity to aspirin – people with an allergic response to aspirin or other NSAIDs (non-steroidal anti-inflammatory drugs) are more likely to develop polyps.
Allergic fungal sinusitis – an allergy to airborne fungi.
Rhinitis/Rhinosinusitis – an inflammation of the nasal passage and sinuses, typically lasting 12 weeks or more. This condition includes hay fever.
Cystic fibrosis – a chronic disease that affects organs such as the liver, lungs, pancreas, and intestines.
Churg-Strauss syndrome – a disease that results in the inflammation of blood vessels.
Age – Nasal polyps can occur at any age, but young and middle-aged adults are more at risk.
Genetics – individuals whose parents have had nasal polyps have a higher risk of developing them.
The exact causes of nasal polyps are not known. Although a significant number of cases are linked to non-allergic asthma, in some cases, no respiratory or allergic trigger is found.
Nasal polyps have no relationship with colonic or uterine polyps found in the digestive system or uterus, respectively.
The exact mechanism of polyp formation is unknown, but most researchers agree that they are the result of swelling (inflammation) in the nose or sinuses – they are not a disease.
Some experts believe that inflammation causes an accumulation of fluid in the interstitial space (space between mucous-forming cells) of the nose and sinuses. Eventually, gravity pulls these heavy cells down, resulting in polyps. Scientists believe possible triggers are bacterial or viral infection, an allergy, or an immune response to a fungus.
Nasal polyps appear most frequently near the openings to the sinuses (in the nasal passage); however, they can develop anywhere throughout the nasal passages or sinuses.
A doctor will generally be able to make a diagnosis after asking about symptoms and examining the patient’s nose. Often polyps are visible with the aid of a lighted instrument.
The doctor may also order the following tests:
Nasal endoscopy – a narrow tube with a small camera (or magnifying lens) is inserted into the patient’s nose.
CT scan – this enables the doctor to locate nasal polyps and other abnormalities linked to chronic inflammation. The doctor will also be able to identify any other obstructions.
Skin prick allergy test – if the doctor thinks that allergies may be contributing to polyp development, he or she may do an allergy test.
Cystic fibrosis – if the patient is a young child, the doctor may order a cystic fibrosis test.