Emotional tears have special health benefits. Biochemist and "tear expert" Dr. William Frey at the Ramsey Medical Center in Minneapolis discovered that reflex tears are 98 percent water, whereas emotional tears also contain stress hormones which get excreted from the body through crying. After studying the composition of tears, Dr. Frey found that emotional tears shed these hormones and other toxins which accumulate during stress. Additional studies also suggest that crying stimulates the production of endorphins, our body's natural pain killer and "feel-good" hormones." Interestingly, humans are the only creatures known to shed emotional tears, though it's possible that that elephants and gorillas do too. Other mammals and also salt-water crocodiles produce reflex tears which are protective and lubricating.