Emotional tears are composed of different chemicals than are tears from eye irritants. Emotional tears are more protein-based hormones, such as prolactin, adrenocorticotropic, and leucine enkephalin (a natural pain killer!), which is suggested to be the mechanism behind the experience of crying from emotion making an individual feel better. Study by Dr. William H. Frey, bio chemist at St. Paul Ramsey Medical Center.
— Lalah Delia