Sinus infection is an inflammation of the sinuses. Sinuses are air-filled spaces in the skull around the nose. These spaces are in connection with the nasal cavity and pharynx, and are lined with mucosa. In case of an inflammation, the mucosa swells, allowing no moisture to be discharged from the space anymore. This causes pain and tightness.


A distinction is made between acute and chronic sinus infection.
Acute sinus infection is in more than half of cases the result of a bacterial or viral infection. In ten percent of cases, dental problems are the cause. Sometimes, the condition is caused by air irritation, pollution or smoke, and the like. The symptoms can persist for three to eight weeks.
In case of chronic sinus infection, there are persistent or recurrent symptoms that usually last longer than eight weeks. A chronic sinus infection may be caused by an improperly treated acute sinus infection, or by an allergy.
Sinus infection is not contagious and usually harmless.


In case of sinus infection, the nose is clogged with elastic mucus. This mucus is usually thick or yellow and bloody. The patient can also suffer from nosebleeds, sneezing and the sense of smell (temporarily) deteriorates. The inflammation causes pain in the upper jaw or molars, severe pain around the eyes and cheeks and headache. The pain occurs mainly when chewing or bending forward.
There are several types of sinuses, thus also several types of sinus infections:

The first three infections look similar to each other. They are often accompanied by local headache, sensitivity at the surface and swelling of the eyelids. A sphenoid sinus infection can also lead to blurred vision due to the proximity of the optic nerves. A maxillary sinus infection is an inflammation of one of the paranasal sinuses. It may be the result of a cold or swimming in contaminated water. Very occasionally, the bottom of the maxillary sinus breaks by extracting a molar. This creates an opening, through which bacteria can get inwards and cause inflammation.


The diagnosis of acute sinus infection is made on the basis of the symptoms. Sometimes, the diagnosis should be confirmed by X-rays, a CT scan or an endoscopic examination of the sinuses.


A sinus infection usually heals on its own. With antibiotics it doesn’t cure faster. It also won’t prevent complications. Only with a deviating course, antibiotics are useful.
In case of an acute sinus infection due to a viral infection, only supportive treatment is needed. With agents for stuffy nose, the blocked feeling is combated. Painkillers help for pain and fever. With the aid of medication for allergies, more allergic reactions in the sinuses are countered.
In people whose treatment has no effect and who continue to suffer from recurrent or persistent sinus infections, rinsing the sinuses (sinus irrigation) or surgery may be required. The type of surgery depends upon which sinus is infected. Rinsing the sinuses is usually done under local anesthesia.


People with uncomplicated acute sinus infection can expect a full recovery. The prospects of a chronic sinus infection varies by individual, but requires a long-term treatment for inflammation and periodic treatment for acute flare-ups. Patients without a significant underlying disease can fully recover. In very rare cases, the infection can be dangerous because the sinuses are close to the brains.