Paranasal sinus disease is a broad term for any condition affecting the air-filled cavities in your facial bones. It most commonly refers to sinusitis, the inflammation or infection of these cavities, but it also covers structural problems, polyps, fungal infections, and rarely, tumors. About 12% of people in the United States have some form of chronic sinus disease, making it one of the most common health conditions overall.
Where Your Sinuses Are and What They Do
You have four pairs of sinuses, each named after the bone it sits in. The maxillary sinuses are the largest, located under your eyes in your cheekbones. The frontal sinuses sit above your eyes in your forehead. The ethmoid sinuses are a cluster of small air cells between your nose and eyes. The sphenoid sinuses are deeper in your skull, behind the ethmoid sinuses.
All four pairs are lined with tissue that produces mucus, which drains into your nasal cavity and flushes out germs and allergens. Your sinuses also warm and humidify the air you breathe before it reaches your lungs, absorb some of the force during head injuries (acting like crumple zones), reduce the weight of your skull, and help give your voice its resonance. When any of these cavities become blocked, inflamed, or affected by disease, the result is what clinicians call paranasal sinus disease.
Acute vs. Chronic Sinusitis
The most common form of paranasal sinus disease is sinusitis, and the distinction between acute and chronic matters because they feel different and are treated differently. Acute sinusitis comes on suddenly, usually after a cold or respiratory infection, and resolves within four weeks. You might have fever, thick discolored mucus, and sharp facial pain. Chronic sinusitis lasts 12 weeks or longer, even with treatment. Fever is uncommon in the chronic form, but the ongoing congestion and reduced sense of smell can significantly affect quality of life.
Common symptoms across both types include:
- Thick, discolored mucus from the nose or draining down the back of the throat (postnasal drip)
- Blocked or stuffy nose that makes breathing through it difficult
- Pain, tenderness, or swelling around the eyes, cheeks, nose, or forehead
- Reduced sense of smell and taste
- Ear pain or headache
The location of pain often hints at which sinuses are involved. Pressure across the forehead points to the frontal sinuses, pain in the cheeks or upper teeth to the maxillary sinuses, and deep pain behind the eyes to the sphenoid or ethmoid sinuses.
Nasal Polyps
Nasal polyps are soft, painless, noncancerous growths that develop on the lining of the sinuses or nasal passages. They form when chronic inflammation causes the tissue to swell and hang down like small teardrops. Small polyps may cause no symptoms at all, but larger ones or clusters can block airflow and mucus drainage, leading to persistent congestion, loss of smell, and recurrent infections.
Polyps are closely linked to chronic sinusitis. When doctors refer to “chronic rhinosinusitis with nasal polyps,” they’re describing a specific subtype driven by a particular pattern of inflammation. This distinction matters because it affects treatment choices, including whether newer biologic therapies might be appropriate.
Fungal Sinus Disease
Most sinusitis is caused by viruses or bacteria, but fungi can also be responsible. Allergic fungal sinusitis is the most common fungal form, developing in people whose immune systems overreact to fungal spores naturally present in the air. It typically causes thick, sticky mucus, nasal polyps, and a characteristic appearance on CT scans. Diagnosis requires confirming an allergic response, finding nasal polyps, identifying fungal elements in the mucus, and seeing specific patterns on imaging.
More aggressive fungal infections can occur in people with weakened immune systems and may invade surrounding tissue. These invasive forms are far less common but are treated as medical emergencies.
Sinus Tumors
Tumors in the paranasal sinuses are rare, accounting for a very small fraction of all head and neck cancers. They can be noncancerous (like hemangiomas) or cancerous. The most common malignant type is squamous cell carcinoma, followed by adenocarcinoma and adenoid cystic carcinoma. Because the sinuses are enclosed spaces, tumors often grow silently for a while before causing symptoms. Warning signs include one-sided nasal obstruction that doesn’t improve, nosebleeds from one side, numbness in the face, or changes in vision. Any persistent one-sided nasal symptom that doesn’t respond to typical sinusitis treatment warrants further evaluation.
How Sinus Disease Is Diagnosed
Diagnosis usually starts with your symptoms and a physical exam. A doctor may look inside your nasal passages with a thin, flexible scope to check for swelling, polyps, or discharge. For chronic or complicated cases, a CT scan of the sinuses is the standard imaging tool. It shows the extent of inflammation, whether mucus is trapped, and which sinuses are affected. CT scans are also essential for surgical planning. MRI is used less often but can help distinguish between different types of tissue, which is important when a tumor is suspected.
Allergy testing may be recommended if allergic triggers are suspected, particularly in cases of recurrent sinusitis or allergic fungal disease.
Treatment for Inflammatory Sinus Disease
First-line treatment for chronic sinusitis is medical, not surgical. Intranasal corticosteroid sprays are the cornerstone. These reduce inflammation directly in the sinus lining and are recommended for at least one month before judging whether they’re working. Saline nasal irrigation, using a squeeze bottle or neti pot with salt water, helps flush out mucus and irritants and is a simple addition that improves symptoms for many people.
These corticosteroids can be delivered as standard sprays, nasal drops, or through specialized delivery systems designed to reach deeper into the sinuses. For acute bacterial sinusitis, antibiotics may be added, but they’re not helpful for viral infections, which make up the majority of acute cases.
For chronic sinusitis with nasal polyps that doesn’t respond to sprays and irrigation, biologic therapies are a newer option. These are injectable medications that target specific immune pathways driving the inflammation. They can shrink polyps and improve breathing and smell, though they typically need up to six months to show their full effect.
When Surgery Becomes an Option
Surgery is reserved for cases where medical treatment hasn’t provided adequate relief. The standard procedure is functional endoscopic sinus surgery (FESS), performed through the nostrils without external incisions. The goal is to remove tissue blocking the natural drainage pathways of the sinuses while preserving as much healthy lining as possible. By restoring drainage, the sinuses can ventilate and clear mucus normally again.
FESS has transformed sinus surgery over the past few decades. Recovery is generally faster than older open techniques, and most people return to normal activities within one to two weeks. In some cases, surgery and biologic therapy are used together, with biologics started around the time of surgery to reduce the chance of polyps returning.
Surgery is not a permanent cure for chronic sinusitis. The underlying tendency toward inflammation remains, so ongoing medical management after surgery, typically with nasal corticosteroids and saline rinses, is important for maintaining the benefits.