Dealing with people occasionally can be quite nerve-racking. One of the causes of stress for some people today is dealing with difficult people at work and this can result to work and environmental pressure which will eventually lead to stress in one's life. Perhaps they are working too many several hours and therefore do not have enough time to spend with loved ones as much as they would love to. Another challenge at work that can cause stress is when your superiors are too demanding to say the least or even yell at you for no real reason. This is enough to make any person feel annoyed as well as stressed out.
You're working long hours and taking work home - under pressure with tomorrow's deadline.