since i was 4 years old. reporter: he was just 17 when one of nascar s top drivers recruited him for his development team. it was just like everything was falling into place in my life, and nothing could stop me. reporter: but something did. i remember being thirsty a lot. i was using the bathroom extremely frequently, losing a lot of weight. reporter: one of the first things his doctors checked, his blood sugar. reed was diagnosed with type 1 diabetes. no, ryan, you ll never race again. reporter: reed found a doctor willing to help him get back on the track. there had been adjustments. a new diet, sensor has been wired into his abdomen that transmits his readings. there s a continuous glucose monitor mounted to the dash inside his race car. that allows him to check his blud sugar during the race. and his fire suit now sports a bull s-eye. we have a guy trained on the pity crew to reach into the window to give me an insulin shot should i need it.