Why do people end up in a coma after overdosing?

Answer 1

Once people start take drugs it's hard for them to stop.So after taking so much they will want more and will not be able to stop.That's when they start taking to much at once.And this is the time when they begin to overdose.

A lot of people have died from doing this.
So that is why it is important to never take drugs.

Answer 2

It depends on the drug and the overdosing interferes with the body's ability to function, so it goes into a coma to preserve essential body functions, and if not successful can result in death.