Sinus infections: Causes and symptoms explained

By Jean Cherry, RN, MBA Sep 27, 2022 • 4 min

What is a sinus infection?

Every year about 1 out of 8 adults will get a sinus infection, or sinusitis, where the lining of the sinuses become swollen and inflamed.

With four sets of hollow cavities that make up the sinuses, is it any wonder that one in the forehead (frontal sinuses), behind the cheeks (maxillary sinuses), between the eyes (ethmoid sinuses) or one deeper behind the ethmoid sinus (sphenoid sinuses) become infected? Which area is the biggest culprit? It is the maxillary sinuses behind the cheeks.

An infection starts when your sinuses are not draining properly, and clear mucus can turn to thick yellow or green. Breathing through your nose becomes even more difficult with severe sinus infections. In rare cases, sinus infections can develop into meningitis (inflammation around the brain and spinal cord), osteomyelitis (a bone infection), a brain abscess or orbital cellulitis (an eye socket infection).

Symptoms of a sinus infection include nasal discharge, facial pain with aching teeth or jaws, cough, fever, ear pressure and headaches.

How long does a sinus infection last?

Generally, people can have a sinus infection for four to 12 weeks. Symptoms lasting longer than 12 weeks are considered chronic sinus infections or recurring sinus infections.

What causes sinus infections?

Colds, allergies, a deviated septum and nasal polyps are a few reasons sinus infections develop.

How do you know if you have a sinus infection?

Knowing if you have a sinus infection vs. a cold is difficult, as a cold can turn into a sinus infection. A cold starts with a runny nose, sneezing and cough that usually resolves within seven to 10 days. If the symptoms progress to include weakness, aches and pains in your cheeks and forehead that spread to your jaw, you may have a sinus infection. Sinus infections can be bacterial or viral. Bacterial sinus infection symptoms typically last longer than a week and include facial pain and nasal drainage that looks like pus.

How to treat a sinus infection

About 70% of people expect to get an antibiotic for a sinus infection, which puts pressure on healthcare providers to give a prescription even if many people don’t meet specific criteria. Most sinus infections clear up on their own and do not require prescription medication. Be aware that as a patient you can do your part so that inappropriate antibiotic prescriptions do not cause an increase in antibiotic-resistant bacteria, increase the cost of care or put yourself at risk for adverse drug reactions.

There are some over-the-counter (OTC) treatments for sinus infections, such as decongestantscorticosteroid nasal sprays and pain relievers that help with symptoms.

If a sinus infection is severe or chronic, sinus infection medicine may include antibiotics. Antibiotics for a sinus infection do not work against viral sinus infections but are effective for bacterial sinus infections. Amoxicillin used to be the recommended first-line treatment. Now many healthcare providers will prescribe Augmentin, which is a combination of amoxicillin and clavulanic acid because it is effective for many strains of bacteria. If you're allergic to penicillin, your healthcare provider may prescribe doxycycline. Cipro is not a recommended treatment choice for sinus infections.

Nasal sprays containing steroids are used to help decrease inflammation and nasal congestion from sinusitis or allergies. Steroid shots are generally not used to treat sinus infections. Your healthcare provider may prescribe a steroid shot in severe cases or when other therapies haven't worked. Steroids are injected through the nose directly into nasal tissues.

Sinus infections and pregnancy

There are special considerations for women who get sinus infections when pregnant because many medications aren't recommended during pregnancy. The American Pregnancy Association says it's OK for pregnant women to use acetaminophen, but that they should avoid using aspirin and ibuprofen. They recommend trying home remedies to help relieve symptoms, such as the use of a heated humidifier to reduce congestion. Contact your healthcare provider if you have a fever, mucus that becomes green or yellow and if you can't sleep or eat. Your healthcare provider can determine if you need antibiotics and prescribe a type generally recognized as safe during pregnancy.

Are sinus infections contagious?

There is disagreement on whether or not sinus infections are contagious. Bacteria, viruses and fungi can be transferred to other people, which can cause sinus infections. But some people get sinus infections from bacteria, viruses and fungi that are already present in their bodies. Generally, many physicians say sinus infections are not contagious.

Are there any home remedies for sinus infections?

Drinking extra fluids can help you stay hydrated and improve sinus infection symptoms. Using saline irrigation and a humidifier can help clear mucus from sinuses. There is little peer-reviewed research on using essential oils for sinus infections. Some people have used tea tree oil for its antimicrobial and anti-inflammatory properties, but there is a lack of clinical evidence that it works. Cineole oil found in eucalyptus was tested on a small group of people with sinus congestion and found to reduce symptoms. Studies on menthol in peppermint oil used in OTC vapor rubs, nasal inhalers and lozenges found it increased congestion. The cooling sensations of menthol made people think they had clearer nasal passages when they were still congested.

How to prevent sinus infections

To decrease your risk of getting a sinus infection, wash your hands often, especially during flu season, avoid secondhand smoke, and stay away from triggers that set off allergies. If you smoke, get help to quit. Sinus infections commonly occur in many adults. Practicing a few of these comfort measures can help manage sinus infection symptoms and avert sinus infections in the future.

Updated June 2021.

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