1. Crying can be scientifically defined as the shedding of tears in response to an emotional state. This is different from “lacrimation” which is the non-emotional shedding of tears e.g reflex tears which serve to protect your eyes from harsh irritants such as smoke, onions etc or basal tears which are omnipresent in our eyes and keep our eyes from drying out.
Crying is part of our emotional human package and can be as a response to strong emotions from anger, stress,pleasure,sadness, suffering or even to physical pain, and can actually make you feel physically and emotionally better. Emotional tears contain a chemical called leucine-enkephalin, an endorphin that reduce pain and improves mood-which is why you feel better after a good cry.
However, emotional tears due to displeasure/unhappiness also contain adrenocorticotropic hormones which indicate high stress. Hence depending on the reason and frequency of crying, crying can be detrimental. If crying is quite often and this is the “sad” kind of crying, it could be a case of depression or a depressive condition , where depression has been found to be associated with a high death rate. In general though, letting out your emotions is healthy. In fact, a study in China shoed that women live longer than men because they cry more often and hence let out their stress and improves their mood…hence the phrase “Having a good cry”