If you want to be wary about complaining too much, she says a good rule of thumb is to make sure you aren't venting about something more than twice with any individual person. There's no real length of time during which you should be complaining, but if you find yourself unable to move on, that's when it might be an issue. And if you really can't stop thinking about how something is stressing you out, to the point where it's affecting your life, it might be something you want to work through with a mental health professional. But for the most part, it's okay to indulge in a little stress-venting every now and then.