Sinusitis occurs when one or more sinuses become inflamed. This can block the affected sinus or sinuses with increased pressure and associated symptoms.

Your sinuses are air-filled cavities in the bones of your face that open into your nose. Inflammation of one or more your sinuses, or sinusitis, usually occurs due to a viral infection. A bacterial infection, allergies, smoking or growths in the nose or sinuses can also lead to sinusitis. Inflammation of the sinus lining causes swelling that might partially or completely block the opening into your nose. Trapped mucus in a blocked sinus leads to increased pressure and an array of possible symptoms.

Facial Discomfort

A blocked sinus can cause facial pressure, pain and tenderness. The location depends on which sinus or sinuses are involved. The maxillary sinuses, which are located in the cheekbones, are most commonly affected by sinusitis. Tenderness and discomfort -- usually in one cheek -- can be a symptom of maxillary sinusitis. With frontal sinusitis, the discomfort is located in the forehead near the eyebrow. Ethmoid sinusitis may cause pain and/or tenderness at the top of the nose between the eyes. Pain behind the eyes also sometimes occurs. Sphenoid sinusitis might cause referred pain felt at the top, front or the back of the head 4.

Upper Tooth Pain

Upper tooth pain can be a symptom of maxillary sinusitis and the associated increased pressure and inflammation. The roots of the upper molars abut the bony floor of the maxillary sinus, which is why these teeth may become painful with sinusitis in this location. If the teeth are affected, several teeth on the involved side typically ache and might throb. Leaning forward might worsen the pain. Sinus-related tooth pain goes away when the underlying sinusitis is treated. However, it's best to have your dentist check your teeth to be sure the pain is not related to a dental problem, such as a cavity, abscess or periodontal disease.

Ear Discomfort

Sinusitis with increased pressure is sometimes associated with ear pressure, fullness and/or popping. These ear symptoms are not directly caused by pressure within the sinus but are rather caused by extension of the inflammation into the nose and eustachian tube, which connects the nasal cavity and middle ear.

Headache

Although many people think headache is a common symptom of sinusitis, headaches caused by sinusitis are relatively rare. In fact, many people who think they're experiencing sinus headaches are actually suffering from migraines, as explained in an April 2009 review article published in "Expert Review of Neurotherapeutics." The one exception seems to be sphenoid sinusitis, with which headache is the most common symptom 3. The headache is most often felt on the top of the head and is aggravated by head movement, coughing and sneezing. While headache occurs frequently with sphenoid sinusitis, this type of sinusitis accounts for only 1 to 2 percent of all cases of sinusitis. Development of a severe headache with sinusitis might signal development of a complication, such as spread of the infection to nearby structures.

Sinusitis is a common condition that is usually caused by a viral infection. In most people, the condition clears with appropriate treatment. See your healthcare provider if you experience symptoms that might signal sinusitis to determine the best treatment plan. Seek medical care right away if you experience any warning signs or symptoms, including:

• Fever or chills
  
• Redness or swelling of the cheek or eye area
• Impaired vision
• Severe headache
• Drooping or paralysis of one side of the face 
• Confusion, agitation or other mental changes

Reviewed and revised by: Tina M. St. John, M.D.