The reason for stress can be internal or external factors. While external factors has to be dealt on a case to case basis, internal factor is mostly related to self motives. It is easy to find the reason of stress if we ask ourselves. Over expectation, getting ahead in race, achieving results faster, adopting unfair means, etc. are few internal factors (motives) which can take sleep away. Work on it. Simplify things. Clean them. Live a stress free life.