Crying is a more complicated process than one would at first imagine. First of all, there are really three different types of tears.
- Basal tears keep our eyes lubricated constantly.
- Reflex tears are produced when our eyes get irritated, like with onions or when something gets into our eyes.
- The third kind of tears (psychic) are produced when the body reacts emotionally to something.
Each type of tear contains different amounts of organic substances including oils, antibodies, proteins, hormones and enzymes and are suspended in salt water. Scientists have discovered that the emotional tears contain higher levels of manganese and the hormone prolactin, and this contributes to a reduction of both of these in the body, thus helping to keep depression away. They also contain the neurotransmitter leucine enkephalin, which is a natural painkiller that is released when we are stressed. Many people have found that crying actually calms them after being upset.
We need both laughter and tears to help us function in society. Crying relieves stress, reduces hormone and chemical levels in the body, and helps us return to a calm state. Laughter relieves stress, stimulates healing, exercises certain parts of the body, and helps in human bonding. That is why crying and laughing are beneficial to us both emotionally and physically.
Watch pictures that show how different each type of tears are, at the molecular level: http://www.lifebuzz.com/tears/#!M55Ci