A sinus infection is most often caused by a virus. You are more likely to get one after having a cold or the flu. In some cases, a sinus infection can be caused by bacteria.

You are at higher risk for a sinus infection if you:

• Are older in age
• Have structural problems with your sinuses
• Smoke or are exposed to secondhand smoke
• Are exposed to changes in pressure, such as from flying a lot or deep sea diving
• Have asthma or allergies
• Have a weak immune system
• Have dental disease

Symptoms of acute rhinosinusitis often last around 7 to 10 days. If you have a bacterial infection, they may last longer. They may also get better but then worsen. You may have:

• Face pain or pressure under the eyes and around the nose

• Headache

• Fluid draining in the back of the throat (postnasal drip)

• Congestion

• Drainage that is thick and colored (often green), instead of clear

• Cough

• Problems with your sense of smell

• Ear pain or hearing problems

• Fever

• Tooth pain

• Fatigue

Your healthcare provider will ask about your symptoms and past health. He or she will look at your ears, nose, throat, and sinuses. Imaging tests, such as X-rays, are often not needed.

It can be hard to figure out if a sinus infection is caused by a virus or bacterium. A bacterial infection tends to last longer. Symptoms may also get better but then worsen. Your healthcare provider may take a sample of mucus from your nose to check for bacteria.

Most sinus infections will go away within 10 days. Your body will fight off the virus. If your symptoms seem to get better but then worsen, you may have a bacterial infection instead. Your healthcare provider will then give you antibiotics. Take this medicine until it is gone, even if you feel better.

To help ease your symptoms, your healthcare provider may advise:

• Over-the-counter pain relievers. Medicines such as acetaminophen or ibuprofen can ease sinus pain. They may also lower a fever.
• Nasal washes. Washing your nasal passages with salt water may ease pain and pressure. It can rinse out mucous and other irritants from your sinuses. Your healthcare provider can show you how to do it.
• Nasal steroid spray. This prescription medicine can reduce inflammation in your sinuses.
• Other medicines. Decongestants, antihistamines, and other nasal sprays may give short-term relief. They may help with congestion. Talk with your healthcare provider before taking these medicines.

You can help prevent a sinus infection with these steps:

• Wash your hands well and often.
• Stay away from people who have a cold or upper respiratory infection.
• Don't smoke. And stay away from secondhand smoke.
• Use a humidifier at home.
• Make sure you are up-to-date on your vaccines, such as the flu shot.

Call your healthcare provider right away if you have any of these:

• Fever of 100.4°F (38°C) or higher, or as directed by your healthcare provider
• Pain that gets worse
• Symptoms that don’t get better, or get worse
• New symptoms