We produce tears when we cry because our brain, eyes, and emotions are tightly linked, and tears serve both biological and emotional/social purposes.

What tears actually do

  • Tears are made by lacrimal glands above the eyes and constantly coat the eye to keep it moist, nourished, and protected from dust and germs.
  • When we cry, these glands get “turned up” and release far more fluid than usual, so tears overflow and run down the face.

Three main types of tears

  • Basal tears : Always present, forming a thin film that lubricates the cornea and brings oxygen and nutrients because there are no blood vessels on its surface.
  • Reflex tears : Produced when something irritates the eye (onions, smoke, dust, chemicals); they wash out irritants and help prevent infection.
  • Emotional tears : Triggered by strong feelings like sadness, grief, joy, anger, or relief and are unique to humans.

Why emotions trigger tears

  • Emotional crying starts in the limbic system (especially the hypothalamus and amygdala), brain areas that process strong feelings, which then signal the brainstem and lacrimal glands to release tears.
  • Networks including the periaqueductal gray and anterior cingulate cortex link emotions with automatic body responses like changes in heart rate, breathing, facial expression, and tear production.

Chemical and health side of crying

  • Emotional tears contain more stress-related substances and natural painkillers (like endorphins and leucine enkephalin) than basic lubricating tears.
  • Crying can help relieve tension and sometimes leaves people feeling calmer or “lighter,” likely due to these chemicals plus activation of self-soothing systems like oxytocin release.

Social and evolutionary role

  • Visible tears act as a powerful social signal: they can show vulnerability, need for help, sincerity, remorse, or deep joy, often increasing empathy and support from others.
  • Researchers suggest emotional tears may have evolved to strengthen social bonds and defuse conflict by signaling that someone is overwhelmed or non-threatening.

In short: we produce tears when we cry not just by accident, but because the body uses them to protect and clean the eyes, regulate stress in the nervous system, and communicate powerful emotions to other people.