Tears Have Different Compositions

While they may all look like simple saltwater (Deals), the tears we shed are surprisingly complex and tailored to their specific purpose. The human eye produces a constant, thin layer of basal tears that act as a protective shield, keeping the cornea nourished and clear. When an external irritant strikes—be it dust, smoke, or the sharp fumes from a chopped onion—the eye triggers a flood of reflex tears. These are more watery and are designed to quickly wash away the offending substance and protect the eye from damage.

The most fascinating differences, however, lie in our emotional tears. Scientific analysis has revealed that these tears, shed in moments of sadness, joy, or stress, have a distinct chemical signature. Compared to reflex tears, they contain significantly higher concentrations of protein-based hormones, including prolactin and adrenocorticotropic hormone, which are linked to stress. Most remarkably, they also contain leucine enkephalin, an endogenous opioid that acts as a natural painkiller.

This unique chemical cocktail provides a compelling biological explanation for the cathartic feeling many experience after a "good cry." The theory, pioneered by biochemist Dr. William H. Frey II, suggests that emotional crying is an excretory process. By shedding these stress-induced chemicals, the body is literally ridding itself of the byproducts of emotional strain, which may help restore its chemical balance and contribute to a sense of calm and relief.