Crying is a universal human response defined by the secretion of tears from the lacrimal glands, usually accompanied by vocalizations or sobs. The common belief that shedding tears physically removes “toxins” from the body is a widely held misconception. Biologically, the body’s primary detoxification systems are the liver and the kidneys; tears do not function as a significant excretory route for metabolic waste. This idea originates from the actual chemical differences found in tears produced during emotional distress.
The Scientific Composition of Tears
The true composition of tears reveals why they are not a system for biological detoxification. Tears are approximately 98% water, containing electrolytes like sodium and potassium, which gives them their salty taste. They also contain basic proteins such as lysozyme and lactoferrin, which serve an antibacterial function to protect the eye’s surface. This mixture is similar to other bodily fluids and does not contain the high concentrations of waste products typically found in urine or sweat.
Emotional tears do contain measurable amounts of certain stress-related compounds compared to other types of tears. These include protein-based hormones like prolactin and adrenocorticotropic hormone (ACTH), and leucine enkephalin, a naturally occurring opioid peptide.
While these compounds are linked to the body’s stress response, their presence in tears is in minute quantities and does not constitute a physical “flushing out” of toxins. This slight chemical difference likely contributed to the popular, yet scientifically inaccurate, belief that crying is a form of physical cleansing. The actual bulk of detoxification remains the responsibility of the liver and kidneys.
The Three Biological Functions of Crying
The lacrimal system produces three distinct types of tears, each serving a physiological purpose unrelated to detoxification. The first type is basal tears, secreted continuously to keep the eye lubricated and nourished. These tears form a protective film over the cornea, providing a smooth surface for clear vision and maintaining the health of the ocular surface.
The second category is reflex tears, produced rapidly in response to environmental irritants. Exposure to strong stimuli like smoke, dust, or onion fumes triggers their sudden release. Reflex tears function to dilute and wash away foreign particles, protecting the eye’s surface.
The third type is emotional tears, triggered by strong feelings such as sadness, joy, or distress. Unlike the protective roles of basal and reflex tears, the exact biological function of emotional crying is still being studied. These tears are unique to humans and are thought to play a role in emotional regulation and social communication.
Crying and Emotional Stress Relief
The feeling of release people experience after crying is a genuine effect rooted in neurological and psychological processes, not physical detoxification. Crying involves an emotional outburst that activates the body’s nervous system, initially engaging the sympathetic nervous system, or the “fight or flight” response, which increases heart rate and tension.
Following this initial surge, the act of crying helps activate the parasympathetic nervous system (PNS). The PNS, known as the “rest and digest” system, restores the body to a calmer, more relaxed state. This shift in autonomic nervous system control provides the noticeable self-soothing effect and sense of relief.
Prolonged crying can stimulate the release of natural mood-boosting chemicals within the brain. Endorphins, which are endogenous opioids, act as natural painkillers and contribute to well-being. The release of oxytocin, a hormone associated with bonding and calm, also helps alleviate stress and anxiety. This neurochemical process explains the therapeutic outcome, providing an emotional release often misinterpreted as the removal of physical “toxins.”