According to WebMD, sinus infections can last for weeks if they go untreated. Sinus infections typically have symptoms similar to colds, but symptoms lasting for more than 10 days may be indicative of a sinus infection. Sinus infections are diagnosed through a physical exam and a review of medical history.
According to WebMD, sinus infections are initially treated with medication. Antibiotics are typically prescribed when symptoms last for more than 10 days. Decongestants may mitigate the swelling that occurs in sinuses and nasal passages. Common symptoms include fever, coughing, pressure near the face and eyes, headache, nasal obstruction, post-nasal drip, and a cold that persists or worsens. A sinus infection can be caused by any condition that obstructs sinus drainage channels.