It is not uncommon among professionals to work beyond the 8-5 time slot. Making matters worst, some work is still being brought home particularly during week ends. The argument, there are deadlines to be met, these documents need to be finished right away.
Those reasons are signs of:
2. Accepting more work loads that what you can handle.
In both cases, you need to review your work loads and your schedules. Working longer hours may not be the only solution to ontime delivery. Ask for help. Yell, "I need Help!".
Do not be greedy! Do not take more work than what you can finish on schedule. If there are external influences beyond your control, then document it. It will be a good reference later on before your manager kicks your butt.
Personally, I am not a fan of working beyond my usual working time. Once in a while will be fine but definitely not always. Working longer hours is not a key to a successful career. You might burn out before you realize it. You might not be able to reap the fruit of all your efforts.
Life balance is needed. This idiom says it all. "All work and no play makes John a dull boy". Work to live but do not let work take life out of you.