Early in my working life I saw a couple of workaholics suffer very serious health problems which effected both their careers and personal lives. Hard work can be productive and satisfying, but like anything else it can also be destructive when done to excess.
Its hard finding the right work-life balance, but its a necessary thing to strive for.
Oracle had an over worked programmer. He had a heart attack. In his hospital bed, the executive brought in a laptop so the dying employee could get more work done.