Consequences of drinking almost every night?

Doing anything to much is bad for anyone. My son likes to drink but mostly on weekends. His wife was born with diabetes and may need a transplant. Due to how long my son has drank he will not be able to be a donor. So it is always best to keep care of yourself it will help you and could be of help to others. He now has learned his lessons but to late to help the one he loves.