Nasal polyps are growths inside the nasal cavity. They are caused by an infection which may be triggered by allergens, smoke, dust, or other pollutants. The original infection leads to inflammation and swelling of the nasal passages. As the inflammation gets worse, a grape-like growth begins to form.
The formation of the polyp(s) will lead to blockage of the nasal passage which prevents proper mucus drainage. This in turn, promotes the breeding of harmful bacterial which aggravates any existing sinus infection. And this leads to more inflammation, which leads to more polyps.
People suffering from nasal polyps have been known to lose their sense of smell and taste. There is a particularly aggressive form of polyps that will develop in people who are allergic to aspirin.
Malignacy of nasal polyps is rare, thus requiring no biopsy. However, you should keep in mind that cancer of the sinus does happen and the growths look a lot like polyps. Therefore, if you suspect you have polyps you should see an otolaryngologist and get a CT scan, or an endoscopy.
Treatment for nasal polyps includes oral or steroid sprays for inflammation. Doctors may also prescribe antibiotics for infection. If allergies are the original trigger, then the doctor may prescribe antihistamines.
Surgery is usually the last resort. However, be aware that even with surgery, nasal polyps are notorious for making return engagements. It will probably require medication to control the condition even after surgery is done.