If your stuffy nose and headache last for more than two weeks, it may be more serious than a cold. Winter is prime season for sinusitis, as the condition most often results from the common cold. Allergy sufferers are also more likely to develop sinusitis.

An estimated 31 million Americans develop sinusitis each year, leading to 18 million physician visits and $5.8 billion in overall health expenditures according to the American Academy of Allergy, Asthma & Immunology (AAAAI).

"Early on, the symptoms of colds and sinusitis are similar," said Anju Peters, MD, Chair of the AAAAI Rhinosinusitis Committee. "But if symptoms are worsening after 3-5 days, or if they are present for more than 10 days, then sinusitis is the likely culprit."

Sinusitis occurs when drains in the sinus cavities - hollow areas behind the forehead and cheeks - become blocked due to inflammation caused by a cold or allergies. The blockage prevents mucous from draining normally, leading to infection.

Sinusitis is easily recognized by a green or gray nasal discharge, foul tasting post-nasal drip, facial pain/pressure or light fever.

Sinusitis can last for months, or even years, if not properly treated. A physician will typically prescribe antibiotics to treat the infection and patients may also use decongestants to relieve stuffiness.

An allergist/immunologist is the best-qualified medical professional to diagnose and treat underlying allergies that contribute to sinusitis. Use the AAAAI Physician Referral Directory at http://www.aaaai.org to find an allergist/immunologist near you.

For more information about sinusitis and controlling allergies, visit http://www.aaaai.org.

The American Academy of Allergy, Asthma & Immunology (AAAAI) represents allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic disease. Established in 1943, the AAAAI has nearly 6,500 members in the United States, Canada and 60 other countries.

American Academy of Allergy, Asthma & Immunology