A sinus infection, or sinusitis, is a common condition that affects 31 million people in the United States each year. 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 do not improve within a few weeks, you likely have a bacterial infection and should schedule an appointment with your doctor.
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.
Sub-acute sinusitis symptoms can last for up to three months. This condition is most often linked to bacterial infections or seasonal allergies.
Chronic sinusitis symptoms last for more than three months, but they are often less severe. Bacteria are generally not to blame in these cases. Chronic sinusitis is most commonly attributed to persistent allergies or structural nasal problems.
Anyone can develop a sinus infection. However, certain other health conditions and risk factors can increase your chances of developing one, including:
- a deviated nasal septum (when the wall of tissue that divides your nostrils is displaced to one side)
- a nasal bone spur (a bone growth in the nose)
- nasal polyps (noncancerous growths in the nose)
- a history of allergies
- recent exposure to mold
- a recent upper respiratory infection
- cystic fibrosis, which causes thick mucus to build up in your lungs
- airplane travel, which can expose you high concentrations of germs and germs that are not native to your home region
- a dental infection
- a weak immune system
- smoking, which can irritate the lining of your nasal passages
The symptoms of sinusitis are similar to those of a common cold. They may include:
- decreased sense of smell
- stuffy nose
- headache (from sinus pressure or tension)
- sore throat
- runny nose
It may be difficult for parents to detect a sinus infection in their children. Signs that can help parents recognize an infection include:
- cold or allergy symptoms that do not improve within 14 days
- a high fever (above 102.2 degrees F)
- thick, dark mucus coming from the nose for longer than 72 hours
- a cough that lasts longer than 10 days
Symptoms of acute, sub-acute, and chronic sinus infections are similar. However, the severity and length of your symptoms will vary.
To diagnose a sinus infection, your doctor will ask about your symptoms and do a physical exam. He or she 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. The following tests can be used to help determine the cause of chronic sinus infections:
- CT scan (an imaging test that provides a three-dimensional picture of your sinuses)
- MRI (an imaging test that uses powerful magnets to create images of internal structures)
- a fiberoptic scope (a flexible tube that is passed through your nose and records images of your sinuses)
- an allergy test to identify irritants that may cause an allergic reaction
- a blood test to check for diseases that weaken the immune system, such as HIV
Treatment for Congestion
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 keep you 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, such as Neo-Synephrine
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 do not improve within a few weeks, you likely have a bacterial infection and should see your doctor. He or she may give you an antibiotic to help you fight the infection if you have:
- a runny nose, congestion, or a cough that does not improve after three weeks
- facial pain or headaches
- eye swelling
- a fever
If you are given an antibiotic, you must take it for three to 14 days, depending on your doctor’s instructions. Do not 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 does not 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 does not improve with time and medication.
Because sinus infections can develop after a cold, the flu, or an 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 every year
- eat healthy foods, such as fruits and vegetables
- wash your hands regularly
- limit your exposure to smoke, chemicals, pollen, and other allergens
- take antihistamine medication to treat allergies and colds
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)
- osteomyelitis (a severe bone infection)
Written by: Valencia Higuera
Published on Jul 25, 2012
Updated on Feb 15, 2013
Medically reviewed by George Krucik, MD