stress impact on behaviours?

Hi, I have friend who had very stressful situation last month. Her sister died in car accident and it was incredible shock for him. I have noticed that he has changed a lot since than but I have to say that I have expected it. I would like to know how stress may impact on someone's behavior.

Hi, different people differently react on stressful situations. Also it depends how strong stress is. However usual reactions are anxiety, insomnia, depression and fear of death. Also stress may cause some reactions which may be presented as symptoms of some organ failure. Shortness of breath may be presented, accelerated heart rate, fever and excessive sweating and all these symptoms may be caused by stress.