Crying is one of the most human things we do. It is also one of the strangest. We leak salty water from our eyes when we are sad, frustrated, overwhelmed, or even deeply happy. No other animal does this in quite the same way, and scientists are still working to understand why [2][3].
This article explores what research tells us about tears, from their basic biology to their deep social purpose. It also separates documented science from common myths that still circulate.
Three types of tears, one complex system
Your eyes produce tears from glands around the eye socket, and they serve different purposes [1]. Scientists generally divide them into three categories [2][6].
Basal tears keep your eyes moist, comfortable, and free of dust. They flow constantly, though you rarely notice them. Reflex tears are triggered by irritants like onion fumes, smoke, or an eyelash. They flush the eye to protect it [1].
Emotional tears are the third and most puzzling type. They appear when you feel strong emotions, whether sadness, joy, anger, or awe. Most researchers believe this kind of crying is unique to humans [2][3].
All three types are mostly water, but they also contain proteins, oils, enzymes, and electrolytes [3]. Emotional tears tend to have higher concentrations of certain proteins and stress-related hormones, though the exact function of these differences is still debated [2][3].
The social signal theory
One leading explanation for emotional tears is that they function as a signal to other people. Tears are a clear, hard-to-fake sign that something is wrong [2][5].
Psychologist Randolph Cornelius and others have shown that people read sadness and grief much more accurately on a face when tears are visible. When tears are digitally removed from a photo, observers often cannot identify the emotion at all [2]. This suggests tears evolved, at least in part, to communicate distress and need for support.
Some researchers describe emotional tears as a kind of bargaining signal. In this view, tears signal vulnerability and ask others to reduce the costs they impose on you. They may also help others understand what you value, which can strengthen social bonds [5].
This theory fits with findings that crying often leads to social support. People who receive comfort while crying tend to feel better afterward. Those who cry alone or in unsupportive settings, like a workplace, often do not [3].
What happens in the body when you cry
When an emotion triggers tears, your limbic system, the brain’s emotional center, signals other brain regions that then activate the tear glands [3]. The process involves both the sympathetic nervous system, which arouses you, and the parasympathetic nervous system, which calms you down afterward [8].
Crying also releases oxytocin and endorphins, chemicals that can ease physical and emotional pain and promote calm [6][16]. This is one reason many people report feeling relaxed or sleepy after a good cry.
However, the relief is not automatic. One study found that crying can make people feel worse immediately afterward, but better about 90 minutes later [18]. The benefits seem to depend on the context, the support you receive, and how you interpret the experience.
Myths about tears, clearly marked
Myth: Crying removes toxins from the body. This is a common claim, but it is not supported by evidence. Tears contain metabolic byproducts like any other body fluid, but they do not “detoxify” you [7][17]. The proteins and hormones found in emotional tears are not toxins. They are normal signaling molecules that the body regulates through many systems [7].
Myth: Emotional tears have a completely different chemical makeup from reflex tears. Research from the 1980s suggested emotional tears contain more protein than reflex tears. Later studies have not always confirmed this, and the differences are not as dramatic as often claimed [2][7]. The biochemistry of tears is real, but the story is more nuanced than popular summaries suggest.
Myth: Holding back tears is always harmful. Suppressing emotions can be unhealthy over time, but crying is not the only healthy way to process feelings [6]. What matters most is whether you have ways to acknowledge and manage your emotions, whether through talking, writing, exercise, or other outlets.
The mystery of why humans alone cry
Emotional tears remain an evolutionary puzzle. Animals vocalize in distress, and many produce basal and reflex tears. But no other species is known to shed tears from emotion [2][14].
One hypothesis is that tears evolved from distress vocalizations. Infants cry loudly for care before their tear glands mature. Later, visible tears added a quieter, more private signal. Unlike a loud wail that could alert predators, tears can communicate vulnerability only to those nearby [14].
Another idea is that the physical act of scrunching your face during a cry stimulates tear production. This could be why yawning, laughing, and vomiting sometimes bring tears as well [14]. In this view, emotional tears are partly a byproduct of other facial muscle activity.
Scientists have not settled this question. As one researcher put it, there is no answer yet, only theories [2].
Cultural and gender differences
Crying is universal, but how people cry and how they feel about it varies across cultures. Many societies have norms about who may cry, when, and in what settings. In some contexts, public crying is seen as weakness. In others, it is accepted or even expected during grief and loss [15].
Women tend to cry more frequently than men, often several times more often in studies [3][13]. Researchers attribute this partly to biological factors like prolactin and testosterone levels, and partly to social learning and gender roles [4][8]. Beliefs about whether crying is helpful also shape how people experience it [4].
Is crying good for you?
The honest answer is: it depends. Reflex tears protect your eyes, and that is clearly good [18]. Emotional tears may help you feel better, but only under certain conditions.
Crying seems most beneficial when it leads to social support, when it helps you understand what is wrong, or when it allows you to release built-up tension in a safe setting [3][16]. Crying alone or in an unsupportive environment is less likely to bring relief.
If you find yourself crying often and it disrupts your daily life, talking to a health professional can help. Crying is not a sign of weakness, and neither is seeking support [18].
Disclaimer: This article is for general information only and is not a substitute for professional medical or mental health advice. If you have concerns about your emotional health, please consult a qualified professional. We welcome feedback and corrections. Please contact us if you notice any errors or have suggestions for improvement.
References
- [1] Tear Fluid Protein Biomarkers, ScienceDirect
- [2] Humans Are the Only Animals That Cry — And We Don’t Know Why, Discover Magazine
- [3] All About Emotional Tears, American Academy of Ophthalmology
- [4] Gender roles and crying beliefs, Frontiers in Psychology
- [5] Emotional tears: What they are and how they work, Evolution and Human Behavior
- [6] Is crying good for you?, Harvard Health
- [7] Tears can drain toxins from the body, is it true?
- [8] Neuroanatomy of an unique emotion: why only homo sapiens cries?, Instrumentul Bibliometric National
- [10] Lachen und Weinen in Westafrika, Deutsche Nationalbibliothek
- [13] Why are women more likely to cry?
- [14] Why Humans Cry, Twin Cities
- [15] Practices following the death of a loved one across cultures, Nursing Open
- [16] 9 Benefits of Crying for the Mind and Body, Verywell Health
- [17] Can tears remove toxins? Fake! Frequent tears are harmful to the eyes.
- [18] Reflex or Reaction: How and Why Humans Cry, Cleveland Clinic
