My uncle began to suspect that he might have some nerve problem when his toes and fingers started getting tingly. He couldn't figure out why this was happening, but just kind of ignored it.
Sometime after his fingers and toes started going numb, his elbows felt the same way. He didn't know that this tingling symptom was a sign of diabetes onset. Finally he went to the doctor, and got a diabetes diagnosis and began treatment for per-diabetes syndrome.