A lot of things cause stress, one major thing that causes stress school. One thing from school that causes stress is homework, having to much homework at one time can cause u to melt down and give up. Now you're stress and behind in all your classes.
Another thing that can cause stress is your job. Losing it stresses you a lot because if you have a family you wouldn't have any money to care for them and you would be broke and would be struggling to find a new job. And all of this would cause you stress.