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Sinus Infections (Sinusitis)

A sinus infection, or sinusitis, is a common condition that affects 30 million people in the United States each year, according to the National Institute of Allergy and Infectious Diseases. The infection occurs when your sinuses and nasal passages become inflamed.

The sinuses are small air pockets located behind your forehead, nose, cheekbones, and eyes. The sinuses produce mucus, which is a jelly-like liquid that protects the body by trapping germs. Sometimes, bacteria or allergens can cause too much mucus to form, which blocks the openings of your sinuses.

Excess mucus is common if you have a cold or allergies. This mucus buildup can encourage bacteria and germs to grow in your sinus cavity, leading to a bacterial or viral infection. Most sinus infections are viral, and go away in a week or two without treatment. If your symptoms don’t improve within a few weeks, you likely have a bacterial infection and should schedule an appointment with your doctor.

What Are the Types of Sinus Infections?

Acute Sinusitis

Acute sinusitis has the shortest duration. A viral infection brought on by the common cold can cause symptoms that last between one and two weeks. In the case of a bacterial infection, acute sinusitis may last for up to four weeks.

Subacute Sinusitis

Subacute sinusitis symptoms can last for up to three months. This condition most often occurs with bacterial infections or seasonal allergies.

Chronic Sinusitis

Chronic sinusitis symptoms last for more than three months. They’re often less severe. Bacteria are generally not to blame in these cases. Chronic sinusitis most commonly occurs alongside persistent allergies or structural nasal problems.

Who Is at Risk for a Sinus Infection?

Anyone can develop a sinus infection. However, certain other health conditions and risk factors can increase your chances of developing one. Some of these are a deviated nasal septum (when the wall of tissue that divides your nostrils displaces to one side), a nasal bone spur (a bone growth in the nose), or nasal polyps (noncancerous growths in the nose). If you have a history of allergies or recently came into contact with mold, you may develop sinusitis.

A weak immune system, smoking, or a recent upper respiratory infection have been known to lead to sinusitis. Cystic fibrosis is a condition that causes thick mucus to build up in your lungs. A dental infection can increase your chances of a sinus infection, as can airplane travel, which exposes you to high concentrations of germs.

What Are the Symptoms of a Sinus Infection?

The symptoms of sinusitis are similar to those of a common cold. They may include a decreased sense of smell, fever, stuffy nose, headache (from sinus pressure or tension), fatigue, sore throat, runny nose, or cough.

It may be difficult for parents to detect a sinus infection in their children. Signs of an infection include cold or allergy symptoms that don’t improve within 14 days, a high fever (above 102.2°F), a thick, dark mucus coming from the nose for longer than 72 hours, or a cough that lasts longer than 10 days.

Symptoms of acute, subacute, and chronic sinus infections are similar. However, the severity and length of your symptoms will vary.

How Is a Sinus Infection Diagnosed?

To diagnose a sinus infection, your doctor will ask about your symptoms and do a physical exam. They may check for swelling and tenderness by pressing a finger against your head and cheeks. Your doctor may also examine the inside of your nose to look for signs of inflammation.

In most cases, your doctor can diagnose a sinus infection based on your symptoms and the results of a physical exam. However, in the case of a chronic infection, your doctor may recommend imaging tests to examine your nasal passages and sinuses. These tests can reveal mucus blockages and any abnormal structures, such as polyps.

A CT scan provides a 3-dimensional picture of your sinuses. An MRI uses powerful magnets to create images of internal structures. Your doctor may also use a fiber-optic scope, a flexible tube that passes through your nose and records images of your sinuses. An allergy test identifies irritants that may cause an allergic reaction. A blood test can check for diseases that weaken the immune system, such as HIV.

What Are the Treatment Options for a Sinus Infection?


Congestion is the most common symptom of a sinus infection. To reduce mucus congestion and clear your sinuses, apply a warm, damp cloth to your face and forehead several times a day. Drink water and juice to stay hydrated and help thin the mucus. Use a humidifier in your bedroom to add moisture to the air. Turn on the shower and sit in the bathroom with the door closed to surround yourself with steam. Use over-the-counter decongestants or nasal drops.

Use a medicine, such as guaifenesin, that thins mucus.

Pain Remedies

A sinus infection can trigger a sinus headache or pressure in your forehead and cheeks. If you are in pain, over-the-counter medications such as acetaminophen and ibuprofen can help.


If your symptoms don’t improve within a few weeks, you likely have a bacterial infection and should see your doctor. You may need antibiotics if you have a runny nose, congestion, a cough that doesn’t improve after three weeks, facial pain or headaches, eye swelling, or a fever.

If you receive an antibiotic, you must take it for three to 14 days, depending on your doctor’s instructions. Don’t stop taking your medication early, as this can make the infection come back.

Your doctor will schedule another visit to monitor your condition. If your sinus infection doesn’t improve or gets worse by your next visit, your doctor may refer you to an ear, nose, and throat specialist. The doctor may also order additional tests to determine whether allergies are triggering your sinusitis.


Surgery to clear the sinuses, repair a deviated septum, or remove polyps may help if your chronic sinus infection doesn’t improve with time and medication.

How Can I Prevent a Sinus Infection?

Because sinus infections can develop after a cold, flu, or allergic reaction, a healthy lifestyle and reducing your exposure to germs and allergens can help prevent an infection. To reduce your risk, get a flu vaccine shot every year. Eat healthy foods, such as fruits and vegetables. Wash your hands regularly and limit your exposure to smoke, chemicals, pollen, and other allergens. Take antihistamine medication to treat allergies and colds.

What Is the Long-Term Outlook?

Sinus infections are treatable, and most people recover without seeing a doctor or taking antibiotics. However, tell your doctor if you have repeated or chronic sinus infections. You could have an underlying medical condition, such as nasal polyps.

If left untreated, a sinus infection may cause rare complications, such as an abscess (a collection of pus in the sinus cavity), meningitis (a life-threatening infection that can cause brain swelling), orbital cellulitis (an infection of the tissue surrounding the eyes), or osteomyelitis (a severe bone infection).

Content licensed from:

Written by: Valencia Higuera
Medically reviewed on: Mar 08, 2016: Deborah Weatherspoon, Ph.D., MSN, RN, CRNA

This feature is for informational purposes only and should not be used to replace the care and information received from your health care provider. Please consult a health care professional with any health concerns you may have.
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