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Are sinus infections contagious?

Medically reviewed by Sally Chao, MD. Last updated on March 9, 2022.

Official answer


A sinus infection is not contagious in the same way as a cold or the flu. You can’t catch a sinus infection. You could catch cold or flu germs from someone else originally, and they could at some point lead to a sinus infection, but only about two percent of people with a viral upper respiratory infection end up developing a sinus infection.

Sinus infections are like the second phase of an upper respiratory illness or poor-draining sinus, and it only happens in some people some of the time.

What is a sinus infection?

Sinuses are air-filled cavities in your head that drain into your nose. Your sinuses produce mucus that helps trap and get rid of germs and other particles that you breathe in through your nose. A sinus infection occurs when:

  • Germs get into a sinus and cause swelling (inflammation).
  • Mucous fluid starts to build up inside the sinus and it can’t drain properly.

Sinus infections are almost always caused by viruses, although they can also be caused by bacteria.

Sinus infections can be acute, lasting for up to 4 weeks, or chronic, lasting for longer than 12 weeks. A sinus infection can feel like a cold that won’t go away. Symptoms may include:

  • Facial pain
  • Congestion
  • Headache
  • Thick or discolored nasal mucus
  • Fever
  • Fatigue
  • Loss of smell
  • Bad breath
  • Pain over your teeth
  • Cough
  • Loss of smell
  • Mucus dripping down the back of your throat

Who is at risk for a sinus infection?

Most people with an upper respiratory infection do not end up with a sinus infection.

These are the risk factors for sinus infection:

  • Recent cold
  • Nasal allergies
  • Smoking or secondhand smoke
  • A sinus condition that obstructs drainage (like nasal polyps or a deviated septum)
  • A weakened body defense system (immune system)

How is sinus infection diagnosed?

Your doctor can usually diagnose a sinus infection from your symptoms and physical exam. Imaging studies of your sinuses are usually not needed. Acute sinusitis is diagnosed if you have:

  • Cloudy or colored nasal discharge for up to 4 weeks

Plus one or more of these symptoms:

  • Congestion, blocked nose
  • Pain or pressure in the face, head or eyes
  • Cold symptoms that won’t go away
  • Symptoms that last longer than 10 days
  • Symptoms that get better, then suddenly get worse again

Chronic sinusitis is diagnosed if you have at least two of these symptoms for at least 12 weeks:

  • Congestion, blocked nose
  • Pain or pressure in the face, head or eyes
  • Thick mucous discharge
  • Loss of smell

How is sinus infection treated?

Because sinus infections are usually caused by viruses, antibiotics are usually not needed. Treatment can include:

  • Over-the-counter pain relievers
  • Nasal sprays
  • Salt water nasal irrigations

Chronic sinusitis may need to be treated with antibiotics, because bacteria start to grow in the old mucus that hasn’t drained. Treatment may also include allergy treatment or surgery to remove nasal polyps, open and drain a sinus or correct a nasal deformity.

You may be able to ease sinus infection symptoms by getting plenty of rest and drinking lots of fluids. It may also help to apply a warm compress over your face or take a hot shower. This can loosen up mucus in your sinuses and promote drainage. Drinking alcohol, smoking and secondhand smoke can increase swelling in your sinuses and increase pain and pressure.

Although you may not be able to prevent a sinus infection, you can reduce your risk by social distancing during cold or flu seasons, washing your hands frequently, getting your vaccinations and not smoking.

When to call your doctor

Let your health care provider know if you have symptoms of sinus infection or:

  • Cold symptoms that do not improve in 10 days or get better and then come back
  • Fever that lasts more than 3 to 4 days
  • Sinus infections that come and go several times in one year
  • Severe headache or facial pain
  1. Academy of Otolaryngology-Head and Neck Surgery. Sinusitis. August 2018. Available at: [Accessed November 7, 2020].
  2. Centers for Disease Control and Prevention. Nonspecific Upper Respiratory Tract Infection. Available at [Accessed November 7, 2020].
  3. Centers for Disease Control and Prevention. Sinus Infection (Sinusitis). August 27, 2019. Available at: [Accessed November 7, 2020].

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