Stress at Work

I've recently realized that being stressed at work is something that needs to be avoided by all cause. I understand that there are going to be times that are more stressful then one another, but when you show you are stressed you tend to show it to your co-workers as well as customers. I have an employee who is consistently using curse words and storming out of the pharmacy because she is so stressed. I'm not sure why she acts like this, but it's something that she has always done. I have tried to talk to her and get her to calm down, but I'm not getting anywhere with it. I usually can when she's getting ready to blow and send her outside for a few minutes to calm down, but there are times when I can't stop her. I have learned that the best way is to remove yourself from the situation for a minute and try and get yourself together. Does anyone else have any other suggestions?