When Sharon R.* was about ten years old, she was in a swimming pool with her family and suddenly couldn’t feel the water around her. “I was surrounded by dozens of other kids and their parents,” she recalls. “But even with my head above water, their voices weren’t entering my ears and my brain wasn’t comprehending them. I just observed people in the pool without feeling the sensation of ‘wet’ around me.”

She didn’t realize it at the time, but Sharon, now 30, was having one of her first experiences of dissociation: a psychological phenomenon in which someone feels detached from themselves or from reality. Her dissociative episodes persist today, and although they usually only last for a few seconds at a time, that doesn’t make them any less scary. “Physically, I feel floaty. My skin tingles and I feel outside myself—like someone observing myself observing what I’m in front of,” she says. “I don’t feel solid, but as if I’m above or next to what is happening. I’ve been told that my face goes blank and I don’t blink very often, and I sometimes get a distant look in my eye.”

If this sounds familiar, you’re not alone—in fact, dissociation is a lot more common than you’d think. According to the National Alliance on Mental Illness (NAMI), nearly half of adults will experience at least one dissociative episode in their lives.

According to NAMI, dissociation most often develops as a way for people to deal with trauma. This was true for Sharon, who was sexually abused when she was eight and was diagnosed with post-traumatic stress disorder (PTSD) in her 20s. “From [age eight] until now, I’ve always dissociated,” she says. “Typically, it happens whenever I am overwhelmed with what is happening around me.”

But there are several other reasons people might dissociate aside from PTSD, says Gail Saltz, MD, associate professor of psychiatry at the NewYork-Presbyterian Hospital Weill-Cornell School of Medicine and the author of The Power of Different: The Link Between Disorder and Genius. “Dissociation doesn’t just happen after a traumatic event,” she says. “You could have [non-trauma-related] panic attacks with dissociation, or you could have a dissociative disorder if [dissociation] is the only thing you’re experiencing.”

So why, exactly, does it happen in the first place, and is there any way to stop it from happening? I asked mental-health pros to weigh in—and give some tips for how to navigate a dissociative episode, whether it’s happening to you or someone close to you.

What’s happening in someone’s brain when they dissociate?

You’ve probably heard of the “fight-or-flight” response before—you know, when you’re under extreme stress and your heart rate increases, you start breathing faster, and your body releases a burst of adrenaline. Well, dissociation is a step beyond that, says trauma therapist Colette Lord, PhD. “If the [fight-or-flight] attempt fails, the person can’t get away, or the aggressor is a loved one, then the body tries to preserve itself by shutting down, expending as little energy as possible,” she says. “It’s the last-ditch emergency response system of the body in which the brain prepares the body for injury.”

Researchers have explained this from an evolutionary perspective. While fight-or-flight prepares us to flee from danger, this shut-down “fright” state essentially allows us to play dead—it’s harder (if impossible) to move or speak, our emotions are numbed, and our body’s resources are conserved for impending shock.

Brain imaging studies have shown almost every area of the brain has a decrease in activation during dissociation, Dr. Lord adds. Psychiatrist Daniel Amen, MD, says that his own imaging work around dissociation has shown abnormal activity in the temporal lobes, in particular—the ones associated with speech and hearing—and in the limbic system, which controls emotion and memory. Dr. Lord says that there’s also a chemical component to dissociation. “The body releases its own opioids and cannabinoids, which reduce perceptions of physical and emotional pain and produce calm and a sense of detachment from what is happening,” she notes.

Dissociation can happen during a traumatic event, but it can also continue to recur afterwards. “For those who have developed PTSD and related disorders, their brain remains on high alert for potential danger,” says Dr. Lord. “Their brain responds to things that are even slightly emotionally or physically threatening as though it were a life-or-death situation, and reacts accordingly.” And, as Dr. Saltz previously mentioned, this can also happen independently of a specific trauma. (More on that in a sec.)

What does dissociation feel like?

While dissociation can happen to anyone, regardless of age, gender, or ethnicity, it doesn’t look the same from person to person. “As people have different brain patterns, their symptoms can vary from periods of spaciness, to panic, to rage outbursts,” says Dr. Amen. Someone can also enter a trance state and have no awareness at all of what’s happening around them, adds Dr. Lord.

That said, there are a few distinct categories of dissociation that mental health experts recognize. “Depersonalization is a form of dissociation where you feel like you’re outside of yourself and you don’t have conscious control of your identity,” says Dr. Saltz. “Derealization is another form, which is feeling like things aren’t real in some way.”

Dr. Saltz adds that many people with PTSD have flashbacks to the traumatic event they experienced during dissociative episodes. “Those intrusive flashbacks are like a daydream you can’t stop having, and you’re unaware of what’s going on now.”

In other cases, says Dr. Lord, a person experiencing dissociation can feel like they’re someone else entirely. “For some who were abused as kids, they might get triggered and experience themselves as a small child in how they are reacting and feeling. The person knows that they are an adult, but has a very strong feeling of being a child,” she says. The most extreme form of this phenomenon is dissociative identity disorder (which used to be called multiple personality disorder). “In this experience, the person’s self-states have particular identities and response patterns and have developed a sense of individual autonomy,” Dr. Lord says. “These different parts may not know about or remember what other parts do when they come out.” (An estimated 2 percent of the population have a dissociative disorder such as dissociative identity disorder, per NAMI.)

What triggers dissociation?

Just like there are lots of different forms of dissociation, there are a ton of things that could kick off an episode if you’re prone to them. “Stressful situations, a lack of sleep, low blood sugar, and an emotional memory that reminds one of the initial trauma are common triggers,” says Dr. Amen.

Dr. Lord adds that the prospect of being alone can also lead to dissociation in some people. “One of the primary ways that we as social beings handle threat is to seek social support,” she explains. “So someone who has survived an armed robbery might dissociate when faced with their partner going on a trip for work and leaving them alone, because it feels unsafe, and unsafe is interpreted by their brain as life or death.”

In Sharon’s case, there are two triggers she’s identified. “I tend to dissociate at large events, like conferences or bars, where I’m surrounded by people I don’t know in a place I haven’t been to before. It’s emotionally easier for me to handle a situation if I’m not ‘really there’,” she says. “On the other side of my experience, I dissociate often during intimate times: having sex with a partner.”

But for other people, says Dr. Saltz, dissociation can happen without a clear cause. “There isn’t necessarily a trigger at all, and that’s the problem,” she says. It’s rare, but anyone can experience it, whether or not it’s linked to a specific trauma.

Is there anything you can do to stop dissociation in its tracks?

Experts agree that there are lots of things you can do to reduce the severity of dissociative episodes and even eradicate them altogether. The first step, no matter what the cause of your dissociation, is to seek help from a mental health professional. “From a prevention perspective, getting into good therapy to address and work through the trauma is often essential,” says Dr. Lord. “Once the traumas have been fully ‘digested,’ the likelihood of dissociation greatly decreases and may actually resolve.” Your therapist may also recommend medication (like antidepressants) to help manage mental health issues often associated with dissociation. (Therapy and medication are also the usual course of treatment for people with dissociative disorders.) In the longer term, Dr. Lord says activities that require rhythm and engagement, like dancing or singing, can also be helpful for trauma survivors, as they help connect you with your body and other people.

Experts agree that it’s also important to have an arsenal of grounding techniques at hand, which can be helpful when you feel a dissociative episode coming on. “Taking advantage of every sense you have and rooting your mind in something very concrete can be helpful,” says Dr. Saltz. “So, for example, starting at 100 and counting back in your mind or out loud by threes. Holding something cold, like an ice cube, or smelling something like peppermint oil can help derail or shrink a dissociative episode.” Dr. Amen adds that listening to upbeat music or eating something can also help change your state quickly, while Sharon’s go-to techniques involve snapping an elastic hair tie on her wrist and counting all the green things she can see.

What you don’t want to do, says Dr. Saltz, is to just avoid whatever triggers your dissociative episodes. “Basically, what that does is reinforce [dissociation] as a coping mechanism,” she says. “You’re more likely to help it dissipate if you’re able to recreate those triggers in a therapeutic setting. If you learn to manage the symptoms, you become desensitized to the trigger.”

And what if someone else in your life is the one who dissociates? “Just sit with them and focus on supportive statements, like ‘I’m here with you,’ ‘It’s going to be okay,’ or ‘I’m going to help you,'” Dr. Saltz says. “You can participate in their rooting themselves in the present, but you don’t want to shake them or do something aggressive in making them feel they’re here now. That can actually make the person feel more anxious.”

No matter how much dissociation affects your life, says Sharon, just know help is available. “First of all, you’re not crazy!” she says. “I can’t advocate enough for going to talk therapy and figuring out what your triggers are. It’s taken me years of studying, practicing, and managing it in my life, and it’s hard to be mindful and present—but it’s less scary than escaping.”

*We withheld Sharon’s full name to protect her privacy.