Overworking is absolutely bad for your health, when sustained for longer periods of time. A week every now and then won’t hurt, but months in a row is really bad for your health.

And it’s also bad for your business. Your productivity actually goes down when you work so much, to the point that it can become even less than what you would accomplish in a normal 40-hr workweek. When we overwork ourselves, our cognitive abilities reduce. We lose focus, make mistakes, lose our problem solving skills, overlook the obvious, etc.

So both for your personal health as well as for the health of your business: stop doing this!