Sinus Infection (Sinusitis)

Español: Infección de los senos paranasales (sinusitis)


A sinus infection (sinusitis) does not typically need to be treated with antibiotics in order to get better.  If you or your child is diagnosed with a sinus infection, your healthcare professional can decide if antibiotics are needed.


Sinus infections occur when fluid is trapped or blocked in the sinuses, allowing germs to grow. Sinus infections are usually (9 out of 10 cases in adults; 5-7 out of 10 cases in children) caused by a virus. They are less commonly (1 out of 10 cases in adults; 3-5 out of 10 cases in children) caused by bacteria.

Other conditions can cause symptoms similar to a sinus infection, including:

  • Allergies
  • Pollutants (airborne chemicals or irritants)
  • Fungal infections

Risk Factors

Several conditions can increase your risk of getting a sinus infection:

  • A previous respiratory tract infection, such as the common cold
  • Structural problems within the sinuses
  • A weak immune system or taking drugs that weaken the immune system
  • Nasal polyps
  • Allergies

In children, the following are also risk factors for a sinus infection:

  • Going to daycare
  • Using a pacifier
  • Drinking a bottle while laying down
  • Being exposed to secondhand smoke

Signs and Symptoms

Common signs and symptoms of a sinus infection include:

  • Headache
  • Stuffy or runny nose
  • Loss of the sense of smell
  • Facial pain or pressure
  • Postnasal drip (mucus drips down the throat from the nose)
  • Sore throat
  • Fever
  • Coughing
  • Fatigue (being tired)
  • Bad breath
Anatomy of the sinuses, showing where inflammation occurs and fluid builds up during a sinus infection.

When you have a sinus infection, one or more of your sinuses becomes inflamed and fluid builds up, making it hard to breathe through your nose.

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When to Seek Medical Care

See a healthcare professional if you or your child has any of the following:

  • Temperature higher than 100.4 °F
  • Symptoms that are getting worse or lasting more than 10 days
  • Multiple sinus infections in the past year
  • Symptoms that are not relieved with over-the-counter medicines

If your child is younger than three months of age and has a fever, it’s important to call your healthcare professional right away.

You may have chronic sinusitis if your sinus infection lasts more than 8 weeks or if you have more than 4 sinus infections each year. If you are diagnosed with chronic sinusitis, or believe you may have chronic sinusitis, you should visit your healthcare professional for evaluation. Chronic sinusitis can be caused by nasal growths, allergies, or respiratory tract infections (viral, bacterial, or fungal).

Diagnosis and Treatment

Your healthcare professional will determine if you or your child has a sinus infection by asking about symptoms and doing a physical examination. Sometimes they will also swab the inside of your nose.

Antibiotics may be needed if the sinus infection is likely to be caused by bacteria. Antibiotics will not help a sinus infection caused by a virus or an irritation in the air (like secondhand smoke). These infections will almost always get better on their own. Antibiotic treatment in these cases may even cause harm in both children and adults.

If symptoms continue for more than 10 days, schedule a follow-up appointment with your healthcare professional for re-evaluation.

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Symptom Relief

Rest, over-the-counter medicines and other self-care methods may help you or your child feel better. For more information about symptomatic relief, visit the Symptom Relief section of this website or talk to your healthcare professional, including your pharmacist. Always use over-the-counter products as directed since many over-the-counter products are not recommended for children of certain ages.


There are several steps you can take to help prevent a sinus infection, including:

  • Practice good hand hygiene
  • Keep you and your child up to date with recommended immunizations
  • Avoid close contact with people who have colds or other upper respiratory infections
  • Avoid smoking and exposure to secondhand smoke
  • Use a clean humidifier to moisten the air at home