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.