Rochester, Minnesota - Most people who have a cold feel better in about a week as the virus runs its course. Sometimes colds can lead to inflammation of your sinuses. "A small percentage of people who have a cold virus can go on to develop bacterial sinusitis," says Dr. Nipunie Rajapakse, a pediatric infectious diseases specialist at Mayo Clinic.

"Sinusitis is an infection of your sinuses," says Dr. Rajapakse. "Your sinuses are usually air-filled cavities in your skull. They sit just under your eyes, in your forehead, and between your eyes, as well. If you develop an infection, the sinus cavities can become filled with mucous and pus."

Inflamed sinuses most commonly are caused by viruses, bacteria or allergies. Antibiotics may be prescribed to treat a bacterial sinus infection but will not help a viral infection or provide any relieve allergy symptoms. Many people with bacterial sinusitis also will get better without taking antibiotic.

"Viruses themselves can cause some sinus inflammation, as well, so, sometimes, it can be a bit difficult to differentiate whether your sinus symptoms are just related to a virus or whether you may have a bacteria contributing," says Dr. Rajapakse. If your symptoms last for more than 10 days, it is more likely to be caused by a bacterial infection.

Common symptoms of a sinus infection include:

• Drainage of a thick, yellow or greenish discharge from the nose or down the back of the throat (Yellow or green discharge can be seen with viral and bacterial sinusitis.)
• Nasal obstruction or congestion, causing difficulty breathing through your nose
• Pain, tenderness, swelling and pressure around your eyes, cheeks, nose or forehead that worsens when bending over
• Headache
• Loss of sense of smell