Sinuses are small air-filled spaces behind your cheeks, forehead, and eyes. They connect to your nose through tiny openings. Each sinus has a thin lining that makes mucus. This mucus helps keep the sinuses moist and clean. Your sinuses remain healthy when the openings stay open, which allows the mucus to drain.
Normal sinus structure. Image adapted from Servier Medical Art, https://smart.servier.com, licensed under CC BY 4.0.
Chronic rhinosinusitis (CRS) happens when the lining of your sinuses stays swollen and irritated for more than 3 months. The swelling can block the sinuses, making it hard for mucus to drain. This can cause stuffy nose, pressure in the face, and trouble breathing through the nose.
To be diagnosed with CRS, you need to have both at least 2 key ongoing symptoms and clear signs of swelling or inflammation inside the sinuses:
This is done through either:
Sometimes, these symptoms are not quickly brought to medical attention due to being relatively mild and long-standing. You may also experience ear fullness, headache, fatigue, altered taste, and or cough, though these are not always present and are non-specific.
If you have any of the following, you should let your doctor know: these may suggest something else going on aside from CRS.
There are three main types of CRS. They are grouped based on what’s causing the problem in the sinuses.
CRS without nasal polyps:
This is the most common type. It may be linked to allergies, infections, or breathing in irritants like smoke or pollution.
CRS with nasal polyps:
In this type, soft, non-cancerous growths called polyps form in the nose or sinuses. Polyps can block airflow and mucus drainage. People with this type often also have asthma. Some may also react badly to certain pain relievers like aspirin, ibuprofen, or naproxen. Polyps can be found with a CT scan or nasal endoscopy; if they are big enough they may be seen on physical examination. Doctors aren’t sure exactly why polyps form.
CRS with fungal allergy (Allergic fungal rhinosinusitis):
There is normally a small amount of fungi in the air we breathe. Most people breathe them in without problems. But in rare cases, the body has an allergic reaction to these fungi. This leads to thick mucus and strong sinus inflammation. Special tests, mucus samples, and sinus scans are used to diagnose this condition. It’s quite uncommon and happens more often in the US.
[include image of sinuses with nasal polyps -- likely image to the right of the above text]
There are a variety of possible risk factors for CRS. Often, more than one is involved:
Allergies: If you're often around things you’re allergic to (like dust mites, pet dander, or mold), your sinuses can stay inflamed. This can lead to CRS or make it worse.
Irritants in the air: Breathing in smoke, pollution, or strong fumes over time can irritate your sinuses and raise your risk of CRS. Smoking cigarettes is a risk factor.
Repeated viral infections: Getting viral infections often, like the common cold, can damage the sinuses over time. Even after the virus is gone, inflammation may remain.
Immune system problems: People with very weak immune systems are more likely to get repeated sinus infections, which can lead to CRS. This is relatively rare.
Pre-existing structural problems: Some people are born with narrow or blocked sinus passages. For example, a deviated septum. By themselves, these issues don’t usually cause CRS but may make it more likely if other factors are present.
There isn’t one standard test for everyone with CRS. But based on your symptoms and possible triggers, your doctor may suggest:
CRS is usually a long-term condition. It may not fully go away, but most people can control their symptoms with the right care. Your doctor will likely recommend a mix of the following treatments to help you feel better:
These are the main treatments that most people with CRS start with. Your doctor may suggest using a combination of them together:
These treatments don’t work overnight. Most need to be used every day for weeks before you feel real improvement.
If you have nasal polyps, your doctor may suggest more advanced treatments along with first-line therapy:
Surgery may be an option if medicines haven’t worked well for your CRS. An Ear-Nose-Throat (ENT) specialist uses a small camera (endoscope) to do minimally invasive sinus surgery. They remove swollen tissue or blockages to help open up your sinuses. This also helps nasal sprays and rinses reach deeper into the sinuses and work better.
By itself, surgery does not cure CRS. If underlying risk factors aren't being treated, symptoms can come back. Some people may need another surgery years later.
If surgery is being considered, an ENT specialist will explain the details and what to expect.
Is deviated septum a common cause of CRS? By itself, it is not a common cause of CRS, though can contribute to nasal blockage.
Is CRS contagious? No, CRS itself is not contagious. However, infections that can worsen it (like colds) can be.
Are oral decongestants like pseudoephedrine helpful? No. In fact, chronic use can be quite harmful and lead to increased blood pressure.