Most anesthesia side effects are temporary and go away within 24 hours, often sooner. Depending on the anesthesia type and how providers administer it, you may experience: Back pain or muscle pain. Chills caused by low body temperature (hypothermia). Difficulty urinating. Fatigue. Headache. Itching. Nausea and vomiting. Pain, tenderness, redness or bruising at the injection site. Sore throat (pharyngitis).