This one is new to me: "Chronic Exertional Compartment Syndrome". According to the Mayo Clinic website, CECS is "an exercise-induced muscle and nerve condition that causes pain, swelling and sometimes disability in the affected muscles of your legs or arms" While this should probably go in a "Missed Diagnosis" section thread, it doesn't really fit any of the existing categories. So I'll put it here. http://www.mercedsunstar.com/sports/high-school/article207384179.html In summary, for 2 years, a California high school track star (John Hagerman) had intense pain after every race. Eventually, a sports medicine doctor figured it out. So, a happy ending for Hagerman after 2 years of frustrating misdiagnoses.