Many things can cause a sore throat. These causes include infections with viruses or bacteria, or sinus drainage and allergies, among others. You should see your doctor right away if you have a sore throat with a high fever, if you have problems breathing or swallowing, or if you feel very faint. If you have a sore throat and a fever, but you just feel mildly ill, you should visit your doctor within the next few days if it persists or worsens. If you have a cold with sinus drainage, you may use over-the-counter medicines for short-term relief… Visit your doctor if the cold lasts for more than two weeks, or if it gets worse.