Most sore throats are caused by viral infections, such as a cold or flu. Often you’ll have other symptoms like a runny or stuffy nose, sneezing, cough, a mild fever, and fatigue. It can be hard to tell the difference between a cold and flu, but the flu tends to cause worse symptoms, like high fever and muscle aches. If your sore throat is from a virus, antibiotics won’t help. Instead, gargle with warm salt water and use over-the-counter treatments like lozenges and sprays.