A sinus infection, is a common condition that affects 31 million people in the United States each year, according to the American College of Allergy, Asthma & Immunology. The infection causes your sinuses and nasal passages to become inflamed, and this inflammation is called sinusitis.

The sinuses are small air pockets located behind your forehead, nose, cheekbones, and in between the eyes. The sinuses produce mucus, which is a thin and flowing liquid that protects the body by trapping and moving germs away.

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 become thick and encourage bacteria and other germs to build up 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 1 to 2 weeks, you may have a bacterial infection and should schedule an appointment with your doctor.

Acute sinusitis

Acute sinusitis has the shortest duration. A viral infection brought on by the common cold can cause symptoms that typically last between 1and 2 weeks. In the case of a bacterial infection, acute sinusitis may last for up to 4 weeks. Seasonal allergies can also cause acute sinusitis.

Subacute sinusitis

Subacute sinusitis symptoms can last for up to 3 months. This condition commonly occurs with bacterial infections or seasonal allergies.

Chronic sinusitis

Chronic sinusitis symptoms last for more than 3 months. They’re often less severe. Bacterial infection may be to blame in these cases. Additionally, chronic sinusitis commonly occurs alongside 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, such as:

The symptoms of sinusitis are similar to those of a common cold. They may include:

  • a decreased sense of smell
  • fever
  • stuffy or runny nose
  • headache from sinus pressure
  • fatigue
  • 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°F or 39°C)
  • thick, dark mucus coming from the nose
  • 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.

To diagnose a sinus infection, your doctor will ask about your symptoms and do a physical exam. They may check for pressure and tenderness by pressing a finger against your head and cheeks. They 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-D picture of your sinuses. An MRI uses powerful magnets to create images of internal structures.

Your doctor may also use a fiberoptic scope, which is a lighted tube that passes through your nose. It’s used for directly visualizing the inside of your nasal passageways and sinuses. A sample may be obtained during nasal endoscopy for culture testing to test for the presence an infection.

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.

Congestion

Nasal congestion is amongst the most common symptoms of a sinus infection. To help reduce the feeling of pain from sinus pressure, apply a warm, damp cloth to your face and forehead several times a day. Nasal saline rinses may help to clear the sticky and thick mucus from your nose.

Drink water and juice to stay hydrated and help thin the mucus. You can use an over-the-counter (OTC) medication, such as guaifenesin, that thins 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.

Consider using OTC nasal corticosteroid spray. There are decongestants available OTC, but you may want to consider asking your doctor about these before trying one.

Pain remedies

A sinus infection can trigger a sinus headache or pressure in your forehead and cheeks. If you’re in pain, OTC medications such as acetaminophen and ibuprofen can help.

Antibiotics

If your symptoms don’t improve within a few weeks, you likely have a bacterial infection and should see your doctor. You may need antibiotic therapy if you have symptoms that don’t improve within a couple of weeks, including a runny nose, congestion, cough, continued facial pain or headaches, eye swelling, or a fever.

If you receive an antibiotic, you must take it for 3 to 14 days, depending on your doctor’s instructions. Don’t stop taking your medication earlier than directed, as this can allow the bacterial infection to fester and possibly not fully resolve.

Your doctor may have you 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

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

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, you can:

  • Get a flu vaccine shot every year.
  • Eat healthy foods, such as fruits and vegetables.
  • Wash your hands regularly.
  • Limit your exposure to smoke, chemicals, pollen, and other allergens or irritants.
  • Take antihistamine medication to treat allergies and colds.
  • Avoid exposure to those with active respiratory infection, such as a cold or the flu.

Sinus infections are treatable, and most people recover without seeing a doctor or taking antibiotics. However, tell your doctor if you have repeat or chronic sinus infection issues. 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 walled off collection of infection with pus in the sinus cavity
  • meningitis, a life. threatening infection that can cause brain and spinal cord damage
  • orbital cellulitis, an infection of the tissue surrounding the eyes

osteomyelitis, a bone infection