People who cry might have a reputation of appearing weak or too emotional. This causes some to choke down their emotions instead to appear stronger and in control.
But experts insist that there are some unexpected health benefits for people who cry often, including lower stress levels, a decrease of toxins in the body, and greater emotional awareness.
Crying activates the parasympathetic nervous system in the body to signal to the glands in the eyes to release tears. After the crying session is over, the body is able to slow down its breathing and heart rate to a more controlled pace. This entire experience sends a positive release throughout the body and gives off the feeling of relief for the person. One study from the University of South Florida studied how people felt after crying.
Source - Daily Mail