1 / 12 2 / 12 3 / 12 4 / 12 5 / 12 6 / 12 7 / 12 8 / 12 9 / 12 10 / 12 11 / 12 12 / 12 ❮ ❯ Strep throat rarely causes more serious illnesses such as rheumatic fever, a disease that can cause permanent damage to your heart and heart valves.