I cry in small thing so quick. like if my someone tells shouts no at me i suddenly cry. but why?

Personality ???: Easy crying and one's emotions being closer tot the surface can be an inherent personality trait or it can be a manifestation of a mood disorder such as depression or dysthymia, it could be part of a bigger problem called " mood lability" which has many underlying causes including some identifiable physical ailments, so pleas see a psychiatrist for a face to face comprehensive evaluation.