Wrestling has a serious problem. I've thought for awhile now that they need to reduce the amount of travel and non televised house shows, but that is obviously less money. Guys are dropping like flys once they pass 40 in this industry. The most common issue seems to be heart attacks which is probably a result of drug abuse due to their insane schedule. These guys get really beat up though and put off surgery because they don't want to lose their spot; it's really cut throat.
Drug abuse and steroid abuse are more than likely a major cause of a lot of these guys dying so young. I have to imagine all the bodily trauma they endure doesn't help either. The outcomes are all rigged, but these guys are still hitting the ring or the floor outside of it dozens if not hundreds of times a week.
You see a similar sort of thing with NFL players, albeit more focused on the head injuries.