Sinusitis is an infection that causes the sinuses (moist air spaces within the bones of the face around the nose) to swell or become irritated.

More to Know

The sinuses are four sets of hollow spaces located in the cheekbones (maxillary sinus), the forehead (frontal sinus), behind the nasal passages (ethmoid sinus), and deep in the brain behind the nasal passages (sphenoid sinus). Sinuses are lined with the same mucous membranes that line the nose and mouth.

When someone has a cold or allergies and the nasal passages become swollen and make more mucus, so do the sinus tissues. The drainage system for the sinuses can get blocked, and mucus can become trapped in the sinuses. Bacteria, viruses, and fungi can grow there and lead to sinusitis.

Keep in Mind

Sinusitis is common and easily treated. Your doctor may prescribe oral antibiotics to treat cases of sinusitis that are believed to be caused by bacteria. Some doctors may recommend decongestants and antihistamines to help reduce the symptoms.

Cases of sinusitis caused by viruses usually go away on their own without medical treatment. Acetaminophen, ibuprofen, and/or warm compresses can help reduce any pain. But over-the-counter cold preparations have not been found to be effective in reducing symptoms in kids and may cause unwanted side effects.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.