Time never stops even tough it may seem to when your in a coma. I got amnesia one time from hitting my head when I was 12, by the time I was 13, all my memory came back!!! Now I remember evrything from before! (I'm 16 now)
Yes you do age. Time around you does not stop. Basically a coma is a deep sleep that you don't wake up from until your body is ready. A person can stay in a coma for years or never wake up. It is how your body heals.