Wet face. Red eyes. Smudged mascara. It’s pretty easy to tell when someone’s been crying.
What’s not so clear? Why your body thinks sending salty liquid out of your eyes is an appropriate response to hearing that song that always reminds you of your ex. Does the world really need to know that you get that bent out of shape over Ed Sheeran?
Turns out, what happens when you cry is the result of an interesting chain reaction in your body. And once the process is triggered, it’s pretty hard to close the floodgates. Here’s a look at what goes on in your body when you cry—and the weird reason why you’ll probably feel better after your sobfest is over.
You feel an intense emotion—and the signals in your brain start flying.
Maybe you just got some really crappy news. Or your boss just dumped a ton of extra work on your plate, and you’re super overwhelmed. Or you just met your adorable baby niece for the first time.
Hardcore emotions like sadness, anger, stress, and even extreme happiness are processed in your body as a sign of danger, as if you were being chased by a bad guy or are about to be eaten by a bear. In the face of intense circumstances, the amygdala, an area of the brain that controls emotional processing, sends a signal to the hypothalamus—a pea-sized gland in your brain that’s connected to your autonomic nervous system, explains Ray Chan, M.D., an ophthalmologist at Texas Health Arlington Memorial Hospital. The autonomic nervous system handles functions that you don’t have any control over, like body temperature, hunger, thirst, and yup—crying.
Your heart starts to race, and you feel that lump in your throat.
The autonomic nervous system jump-starts the sympathetic nervous system and accelerates the fight-or-flight response. To help you prepare for impending doom, the fight-or-flight response tries to stop you from performing any nonessential functions, like eating or drinking. As a result, it causes your glottis—the opening between the vocal chords in your throat—to swell up, making your throat feel full and tight. “The body is trying to protect you so you don’t accidentally get any [nasal secretions or tears] in your lungs,” says Patricia Salber, M.D., founder of The Doctor Weighs In.
With your fight-or-flight system fully alerted, you might also experience other symptoms normally associated with sheer terror. Your heart rate might increase, your lips start to quiver, and your voice gets shaky.
Then the waterworks begin to flow.
All this emotion tells your hypothalamus to produce the chemical messenger acetylcholine. Acetylcholine binds to receptors in your brain that send signals to the lachrymal glands—small glands that live beneath the bony rim of your eyes, explains Dr. Chan.
When these glands are stimulated, they start to produce tears. If you only shed a few, they might drain back into your punctums—the tiny tear duct openings at the inner corners of your eyes. But that reservoir fills up pretty quickly. And when it does, the tears will start to drip out of your eyes and stream down your face, Dr. Salber says. The tears will also start to flood your nasal cavity and come out of your nose.
Experts don’t completely know why intense emotions make us cry. But they have plenty of theories. Some evolutionary psychologists think that crying is used to send a signal to others that we’re in pain and need help. “Emotional tears have more protein, and there’s speculation that the protein makes the tears thicker, so they’re more likely to hang onto your cheek and send a signal of visual distress,” Dr. Salber says.
Tears may also have a protective mechanism, explains Dr. Chan. They literally coat the surface of your eye, acting like shields to protect your eyes during a dangerous situation. Some experts even think that tears are the body’s way of telling you to throw up a white flag during a fight: The salty drops blur your vision, making you less likely to act aggressive or defensive.
But when it’s all over, you might actually feel better.
When you’re about to cry, your first instinct might be to try to hold back those tears. But letting them out might actually be the smarter move. Tearing up can also signal your brain to release endorphins called leucine-enkephalins, which act like pain relievers to boost your mood. “So people start to feel a sense of relief,” says Dion Metzger, M.D., a psychiatrist based outside of Atlanta.
But this uplifting effect doesn’t happen for everyone. One study examining over 1,000 crying episodes of 97 women, published in the Journal of Research in Personality in 2011 found that the mood benefits of crying are selective and may be shaped by the social environment and affective characteristics of the crier. People with mood disorders (like anxiety or depression) are also less likely to experience the positive benefits of crying, Dr. Metzger says.
So, depending on your circumstances, crying might make you feel better, or it could simply remain a byproduct of human evolution. Either way, there’s no shame in shedding a few tears—even if it’s because of Ed Sheeran.