Here, we dive into the signs and symptoms, causes, and potential complications of nasal polyps.

What Are the Signs and Symptoms of Nasal Polyps?

According to Johns Hopkins Medicine, common signs and symptoms of nasal polyps include:

CongestionLoss of taste and smellCoughSinus pressureRunny noseHeadacheSnoringPostnasal drip (the sensation of constantly needing to clear your throat)

“A large part of why polyps cause these signs and symptoms simply has to do with mass effect: the polyps physically obstruct the flow of air and odors to the appropriate places in the nose,” says Alexander Schneider, MD, a board-certified otolaryngologist at Northwestern Medicine Central DuPage Hospital in Winfield, Illinois. Many of the signs and symptoms of nasal polyps are the same as other conditions that affect the nose and sinuses, including the common cold. This can make it difficult to tell if polyps are the cause of your issues. For this reason, the Mayo Clinic recommends seeing a doctor if your symptoms last more than 10 days. An ear, nose, and throat (ENT) doctor diagnoses nasal polyps visually by peeking inside the nose with a small thin telescope (nasal endoscope), per Johns Hopkins Medicine. If they find polyps, they may suggest various treatment options. Nasal corticosteroid (“steroid”) sprays, oral corticosteroids, and biologic medications can shrink polyps or eliminate them entirely, Dr. Schneider says. But if medications don’t work, your doctor may recommend a minimally invasive procedure to remove the polyps, according to Johns Hopkins Medicine. But nasal polyps often grow back and require long-term management, Schneider says.

What Causes Nasal Polyps?

There’s still a lot we don’t know about what causes nasal polyps. They tend to develop in people with conditions that trigger long-term irritation and inflammation in the nasal passages or sinuses, per the Mayo Clinic. This includes people with asthma, allergies, drug sensitivities, repeat infections, and certain disorders. For example, nasal polyps are present in up to 86 percent of people with cystic fibrosis (CF), per the American Academy of Allergy, Asthma, and Immunology (AAAAI). CF is a genetic disorder that causes breathing and digestion issues, says the Centers for Disease Control and Prevention (CDC). People with CF have mucus that’s too thick and sticky, which blocks airways and traps germs, per the CDC. But nasal polyps are perhaps most often associated with chronic rhinosinusitis (CRS). This long-term condition occurs when your nasal passages and sinuses become inflamed and infected due to trapped fluid, per Northwestern Medicine. According to the AAAAI, CRS affects almost 12 percent of the adult population, and about 20 percent of people with CRS have nasal polyps. Still, there’s a lot we don’t yet know about what causes nasal polyps. According to the Mayo Clinic, some experts believe that people who develop polyps have different immune system responses and chemical markers in their mucous membranes. More research is needed.

Can Nasal Polyps Be Cancerous?

Nasal polyps are typically noncancerous growths that appear on both sides of the nasal passages and sinuses, notes the AAAAI. One-sided nasal polyps, on the other hand, may be cause for concern. “Patients should worry if they have symptoms on just one side of their nose,” says Chester F. Griffiths, MD, a fellow of the American College of Surgeons and chief of endoscopic sinonasal and skull-base surgery at Pacific Neuroscience Institute in Santa Monica, California. “That’s a unique situation that would require a biopsy, because it could be a tumor.” Research suggests tumors make up a small percentage of the diagnoses. In a study published in April 2018 in Northern Clinics of Istanbul, only eight (4 percent) out of 195 cases of single-sided polyps were found to be tumors. The other 187 (96 percent) of cases were noncancerous. According to Dr. Griffiths, single-sided polyps can be mistaken for other single-sided conditions, such as a deviated nasal septum or sinus mucocele. Still, it’s a good idea to get single-sided polyps checked out, just in case.

Potential Complications of Nasal Polyps

If left untreated, nasal polyps will continue to grow, “and they will eventually cause a complete blockage of the nasal airflow,” Griffiths says. This congestion can have a major impact on your quality of life. When the nasal passages are blocked, people begin mouth breathing, which can impact sleep. “There’s a thing called sleep-disordered breathing that occurs with mouth breathing, and it’s a very significant sleep disorder,” Griffiths says. Obstructive sleep apnea, a potentially serious condition in which you stop and start breathing during sleep, is a common type of sleep-disordered breathing, per StatPearls. Your nose is your body’s preferred airway because it takes less effort to breathe through your nose than through your mouth. Plus, breathing with your mouth closed keeps your tongue anchored in place. “When you breathe through your mouth, you lose the anchor of your tongue, so your tongue slides back into your airway and causes further obstruction,” Griffiths says. Blocked nasal passages and sinuses can also make you more susceptible to asthma flare-ups and sinus infections, per the Mayo Clinic. In severe cases, an infection associated with nasal polyps can spread into the eye socket or even the brain, Griffiths says. CRS, for example, can cause reduced vision or possibly blindness if it spreads to the eye socket, and inflammation of the membranes and fluid surrounding the brain and spinal cord (meningitis), according to the Mayo Clinic. But these complications don’t happen often, “because most people treat their symptoms,” Griffiths notes.