In 2011, Elizabeth Banks made an over-the-top video to shock women into heeding the particular signs of the female heart attack. Now, alarming new research says dangerous episodes with hardly any symptoms are more common than even Hollywood could have imagined. Ladies, meet the truly silent heart attack.

Travis Stork is a pretty cool customer. It's what you'd expect from someone who's seen every kind of medical disaster come through the ER where he's an emergency medicine physician—and witnessed every manner of overdramatized medical-disaster portrayal coming out of Hollywood, where he's cohost of the daily TV talk show The Doctors.

As a result, he's both passionate about informing women about worst-case scenarios and also totally put off by the fearmongering it can often lead to. So, when it comes to silent heart attacks—a problem that science has recently discovered may affect far more of us than anyone knew—he's torn.

More than ever, Stork wants to grab women's attention, to take them by the shoulders and tell them to be on alert for the signs. He also wants them to know that the symptoms are not always like the ones in the much-watched Elizabeth Banks video pictured here, in which Banks plays a busy mom trying her best to ignore signs she's having a "little heart attack." (Want to pick up some healthier habits? Sign up to get daily healthy living tips delivered straight to your inbox!)

Banks's character weathers all the signs of a woman's heart attack: nausea, jaw pain, chest pressure, the works. Stork worries about it scaring people.

"You might want to take that video with a grain of salt," he said.

Yet, at the same time, he talks freely of the need to alert us to what he's witnessed. He's seen a woman come into his ER who felt inexplicably more tired than usual while cleaning the house. Another patient's left hand simply felt a little heavy. Still another got winded while carrying boxes of Christmas decorations down to her basement. In all these cases, the women were having heart attacks and had no idea.

We now know this is more common than you'd think, and Stork is still figuring out exactly how to guide us.

"You're walking that fine line between informing people and freaking them out so much that every single time they have a hot flash, they're like, 'Oh, my God, I'm having a heart attack,' " he said.

While the American Heart Association estimates that 155,000 Americans have silent heart attacks each year, surprising new research from the National Institutes of Health suggests the phenomenon is even more widespread and less recognized than previously thought: As many as 8 percent of purportedly healthy people may have scarring on their heart muscles, a classic sign of a past heart attack, Stork says. In 78 percent of people with scarring, symptoms went unrecognized by their doctors or on an EKG (the study used a powerful type of imaging that's less common). This suggests that an astonishing 6 percent of people have had attacks and not realized it.

Yes, 1 in 16 of us may suffer a hidden attack. (Put another way, 15 in 16 never will.) By recognizing unusual discomforts, by not shrugging off a sense that something's going on, women can forestall attacks or limit damage that hidden heart disease will do over the long run.

"It gets back to intuition, to not ignoring it," Stork said. "Messages like Banks's video are a gentle reminder: OK, it may not happen just like this, but if you're having anything that resembles this at all, don't ignore it."

Don't ignore what's out of the ordinary, in other words: Nearly 71 percent of women in one study of heart attack victims experienced unusual exhaustion in the weeks before, half had trouble sleeping, and 42 percent battled shortness of breath. (About 43 percent had zero chest pain.) The woman who felt tired while cleaning her house told Stork nothing more than she knew something wasn't right, although she couldn't tell him what that was exactly.

"When I hear 'I just don't feel right,' that makes me instantly worried," he said.

Stork's patient whose left hand felt heavy said, "I've never felt this before, and I guess I did feel a little rundown over the last day or so," he recalled.

Even when women do have the more typical heart attack symptoms, like chest pain and shortness of breath, those symptoms can sometimes last a few minutes or can come and go as we carry the groceries upstairs, Stork said. And in women, it is important to know that heart attacks may present with only flulike symptoms—nausea, fatigue, or unexplained generalized weakness.

"I see a lot of women who feel sheepish," he said. "They often worry that they overreacted by coming to the ER." Well. Let this story be the end of the second-guessing.

What's going on during these bizarre attacks?

Barely noticeable heart attacks differ from dramatic ones due to differences in biology and blockages. Any heart attack basically means a part of the heart muscle is dying, even just a few cells, due to a lack of blood flow caused by a buildup of cholesterol and other fatty deposits called plaques. Though plaques can accumulate along artery walls over years, they can block blood at the drop of a hat: If plaques suddenly rupture inside an artery, blood clots form, stopping the flow.

"Poor blood flow means decreased oxygen, and when you're not getting enough oxygen to any muscle, that muscle eventually starts dying," Stork said.

If you get yourself to a hospital and doctors can break up the blockage quickly enough (usually with clot-busting meds or an angioplasty to open blocked arteries), the damage can be limited.

"The longer you wait, the more of the heart muscle dies," he said.

Heart attacks can last several hours; irreversible damage can be done after just 20 minutes of blocked blood flow.

In men, plaque is more likely to rupture, but in women, arteries are more likely to become blocked slowly and subtly. Experts think that's due at least in part to the protective benefits of estrogen, which not only helps preserve the arterial lining and keep arteries pliable and healthy, but also increases levels of good cholesterol and decreases bad cholesterol, lowering your risk of plaque ruptures.

"When plaques rupture, it's an explosive, dramatic event," said cardiologist Suzanne Steinbaum, director of women's heart health at Lenox Hill Hospital in New York City and Go Red for Women physician spokesperson.

Ruptures lead to the kind of tight and clenching pain we're used to seeing men experience, at least in the movies.

"When the plaque doesn't explode, and rather builds up slowly over time, it causes more of those subtle symptoms," she said.

It's obvious enough to our brains when a plaque rupture takes place and the lack of oxygen triggers chest pain. A subtle loss of blood flow, however, can be misinterpreted, Stork said.

"By the time the communication signals from your poorly oxygenated heart muscle travel up your spinal cord to your brain," he said, "your brain might translate that as 'Wow, my arm's tingly!'"

Symptoms like pain, tingling, and even shortness of breath may also be due to the fact that during an attack your heart simply can't provide your body with enough blood to function normally.

MORE: Top 10 Cholesterol-Fighting Foods

OK, so what about next time you feel a little off?

It's not just your brain that's confused.

"A heart attack can be a confounding diagnosis, even for clinicians," Stork said.

Early in his career, he saw a patient who arrived at the emergency room feeling nauseated and complaining of abdominal pain. She'd previously had gallstones, those intensely painful hardened deposits that settle in the gallbladder, and she still had her gallbladder, which would lead many an ER doc to think that her discomfort was due to another bout of stones.

But the woman's pain felt just a little bit different from last time, she said. He reverted to investigator mode: Her discomfort wasn't reproducible, doctor-speak meaning that when he pressed on her abdomen, she didn't launch off the table in pain like he'd expect with gallstones. Reproducible pain, he explains, means you can essentially summon it on command by pressing a painful spot or moving an aching joint. Pressing on your abdomen or chest usually won't worsen pain if you're having a heart attack, he said.

Knowing one way or the other about reproducibility is one piece of the puzzle that Stork has resorted to even on himself: He recently jolted awake in the middle of the night with some chest pain of his own. Pressing his chest muscles to see if the pain was reproducible, he remembered he had banged out an extra set of push-ups the day before. His "chest pain" was easily reproducible with a little prodding and, in his case, was just chest muscle soreness in disguise.

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Think you might need to go to the ER? 3 things to consider

So you feel off...but how off is off enough to escort yourself to the front of the triage line? It's always better to go get checked out if you're even slightly concerned, but if you really can't decide whether your symptoms warrant an ER visit, here are a few things that might help you make up your mind.

1. Is it heartburn? It can feel similar to a heart attack, but heartburn is more likely to occur after you eat a big meal or something spicy, or while you're lying down. Reflux pain typically feels more like a burning sensation than the squeezing, aching, or tightness of a heart attack. Heartburn discomfort also doesn't move into your neck or arms like heart attack pain can.

2. Have you ever felt like this before? Be honest. Yes, you're wiped, you're stressed, you're cold and clammy, but does this feel like last winter's flu or something entirely new and different?

3. Do a gut check. What does your instinct say? Does this feel like a major event or not?

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"Fortunately, symptoms that seem like a heart attack often are due to things much more benign," Stork said.Stork and Steinbaum both say when in doubt, get yourself to the ER. Best-case scenario, it's (huge relief) not a heart attack.

A heck of a lot of times, it's plain old heartburn. In fact, of the more than 8 million ER visits Americans make each year for chest pain, more than half of those ruled not to be heart-related end up being acid reflux. The two can feel awfully similar, especially if the heartburn's severe. But if you've had it before, you'll likely know if it's your usual reflux, he says. (Here's how to tell whether it's heart burn or a heart attack.) In the moment, many of us consider a possibly unnecessary pit stop at the ER not worth the trouble; after all, we've got a meeting in 20 minutes or are racing to pick up the kids. But if there's a little voice telling you this time is different, listen to it.

If you miss it, you miss it, right?

Say the worst-case scenario comes true, and you've had a silent attack. While a subtle one that leaves no outward signs of damage behind would seem to be the "best" kind, the hidden plaque buildup that caused it remains brutally problematic in the long run.

The plaque can continue to accumulate and cause a second attack—and with each attack, the harm to the heart muscle keeps adding up, and the risk of heart failure (when the heart can't pump enough blood) or sudden cardiac arrest (when the heart simply stops working) does, too, Steinbaum said.

Damaged muscle gives way to stiff scar tissue that prohibits the heart from beating properly, and the disease process can continue to narrow arteries and impede blood flow. This is ultimately what leads to heart failure. More than a third of people who have a heart attack will develop heart failure in the 7 to 8 years afterward.

That's why Stork said we should never fear a heart attack diagnosis. If you don't get diagnosed, you don't get treatment, leaving in place the blockage that caused the problem to begin with. You also don't get any follow-up—medication for blood pressure and/or cholesterol, and the usual diet, exercise, and stress mandates—that can dramatically ward off your chances of a future heart attack or further damage.

It's time to reckon with your inner procrastinator.

Raise your hand if you're worried! Raise your hand if you're racking your brain to recall every time your arm tingled or you felt cold and clammy! If you're now convinced you've had one of these attacks, get checked out. Depending on the symptoms you had and your family history of heart problems, a doctor might put you through a stress test, which monitors blood flow to your heart while you chug through increasingly challenging exercise.

Julie Llamas Rickman, the woman who felt out of breath putting away her Christmas decorations, knows you think you're superwoman, because she did, too. She threw four or five different holiday celebrations that unseasonably warm December. She was only 41, and it didn't occur to her to scale back on her overscheduled life, even though she knew her huffing and puffing was unusual. Assuming something was up with her asthma, she eventually sought treatment for it, but after finding her allergist's office closed, she made her way to the ER, where doctors informed her she had actually had a heart attack. Sometime in, oh, the past 4 weeks. Like many of us, she didn't think heart attacks could ever go entirely under the radar.

"I was pretty much in denial," she says now. "The hardest part has been that I don't know when it happened." Now, at 46, Rickman's lost 45 pounds (and is still losing), has recommitted to an exercise plan, and recently ran her first 10K. "It's such a scary thought to realize I could have missed out on my son's life," she says. "I want to see him grow up and know who his mother is. Now I'm teaching him health by example."

This article originally appeared on Prevention.com.