Crying when sad? Pretty common. You’ve probably done that a time or two yourself. Maybe you’ve also cried in fury or frustration at some point — or witnessed someone else’s angry cry.

But there’s another kind of crying you might have some experience with: happy crying.

You’ve probably seen this in any number of movies and TV shows, but if you’ve ever felt overcome with joy or success, you might’ve cried some happy tears of your own.

Tears of joy can be somewhat confusing, especially if you associate crying with unwanted emotions. But they’re completely normal.

Happy tears aren’t specific to age or gender, so in theory, they could happen to just about anyone who experiences emotions.

But why do they happen? No one has a definite answer, but scientific research offers a few potential explanations.

Most people think of sadness, anger, and frustration as negative. People generally want to be happy, and you’d probably have a hard time finding someone who views happiness as negative. So, what gives with the happy tears?

Well, happiness does share one similarity with other emotions: Positive or negative, they can all be pretty intense.

According to research from 2015, happy tears happen when you experience emotions so intense they become unmanageable. When these emotions begin to overwhelm you, you might cry or scream (perhaps both) in order to help get those emotions out.

After ripping open your college acceptance letter, for example, you might’ve screamed (so loudly your family thought you’d seriously injured yourself) and then burst into tears.

Dimorphous expression

Happy tears are a great example of dimorphous expression. Here, dimorphous means “two forms.” These expressions come from the same place but show up in different ways.

Here’s another example: Have you ever seen something so cute, such as an animal or baby, that you had an urge to grab and squeeze it? There’s even a phrase you might’ve heard, perhaps from an adult to a small child: “I could just eat you up!”

Of course, you don’t want to hurt that pet or child by squeezing it. And (most?) adults really just want to cuddle and hold babies, not eat them. So, this somewhat aggressive expression of emotion may seem slightly odd, but it does have a straightforward explanation: The feelings are so intense that you simply don’t know how to handle them.

Finding a balance

Difficulty managing emotions can sometimes have negative consequences. Some people who regularly have a hard time with emotional regulation might have mood swings or random outbursts.

In a way, then, these happy tears protect you by giving some balance to extreme feelings that might otherwise have an impact on your emotional health. In other words, crying can come in handy when you feel so overcome you don’t know how to begin calming down.

When you cry for any reason, you send a message to anyone who can see you (whether you want to or not). The act of crying lets others know your emotions have overwhelmed you, which can in turn signal that you’re in need of some support or comfort.

“Sure,” you might think, “who doesn’t want to be comforted when they’re feeling sad or stressed?”

But when you’re utterly happy, you might also want some support. More specifically, research from 2009 suggests you want to bond with others over those extreme emotions you’re experiencing, from happiness to joy to even love.

Humans are, generally speaking, social creatures. This social nature can play a part in the desire to share intense experiences and seek solidarity and comfort in good times as well as bad. Happy crying, then, may be one way of saying, “Please share this wonderful moment.”

The authors of the study mentioned above also point out that tears can signal the magnitude or importance of certain significant events, such as graduations, weddings, or homecomings.

Crying tells everyone around you, “What’s happening right now means a lot to me.” In this way, crying serves an important social function, especially when you feel too overcome to string a sentence together.

Many people dislike crying, even out of happiness. Your nose runs, your head might hurt, and, of course, there are the inevitable stares from strangers when you’re lucky enough to be overcome with emotion in public.

But crying actually has a lot of benefits.

Happy hormones

When you cry, your body releases endorphins and oxytocin. These hormones can help relieve pain, boost your mood, and improve general well-being.

And since tears can help you attract comfort and support from others around you, crying helps increase your sense of connection, which can improve your mood and overall wellness.

Crying from sadness and anger can help relieve these emotions and may make your situation seem a little less bleak.

But when you cry with happiness, the oxytocin, endorphins, and social support can magnify the experience and make you feel even better (and maybe cry a little more).

Emotional release

It’s also worth noting that many happy moments don’t just come about randomly. Getting married, giving birth, graduating from high school or college, being hired for your dream job — these accomplishments don’t come easily. To achieve these milestones, you probably put in plenty of time, patience, and effort.

No matter how fulfilling this work was, it most likely triggered some stress. Crying, then, can be the ultimate catharsis, or release, from this prolonged stress.

Another theory about happy crying suggests these tears happen because your brain has trouble distinguishing between intense emotions.

When you experience a strong emotion like sadness, anger, or joy, a region in your brain known as the amygdala logs that emotion and sends a signal to the hypothalamus, another part of your brain.

The hypothalamus helps regulate emotions by signaling your nervous system. But it doesn’t tell your nervous system exactly what emotion you experienced, because it doesn’t know. It just knows the emotion was so extreme that you might have some trouble managing it.

One of the many important functions of your nervous system involves helping you respond to stress. When you face a threat, the sympathetic branch of your nervous system prepares you to fight or flee.

After the threat has subsided, the parasympathetic branch of your nervous system helps you calm down.

When your nervous system receives that signal from the hypothalamus saying “Hey, we’re a little overwhelmed here,” it knows it needs to step up.

One easy way to do this? Produce tears, which help you express intense emotions, both happy and sad, and help you recover from them.

Tears are a normal human response to intense emotions. While you might be more likely to cry in response to sadness, tears of joy aren’t anything unusual. Turns out, they’re actually pretty helpful.

Crystal Raypole has previously worked as a writer and editor for GoodTherapy. Her fields of interest include Asian languages and literature, Japanese translation, cooking, natural sciences, sex positivity, and mental health. In particular, she’s committed to helping decrease stigma around mental health issues.