You may know all about the “classic” signs of a stroke—sudden one-sided weakness…a loss of balance, speech or coordination…paralysis. But not all strokes come with those clear signs that raise a red flag. More generalized symptoms that could be caused by lots of things—such as headache and dizziness or temporary numbness—can also be symptoms of a stroke. Doctors in the emergency room (ER) are responsible for deciding whether such symptoms are benign, related to some other ailment or whether the person in front of them is having a stroke or transient ischemic attack (a TIA, or prestroke).

Too often, doctors get it wrong.

According to new research from The Johns Hopkins School of Medicine in Baltimore, tens of thousands of strokes and TIAs are probably missed and diagnosed as something else each year in hospital ERs. Those mistakes put people at great risk for future strokes. What’s more, certain population groups, such as women and minorities, are more at risk than others for being misdiagnosed when they come to the ER and actually are having a stroke.


To get to the bottom of how often strokes are missed and misdiagnosed in ERs—and which patients are involved—the researchers searched a database that included ER, hospital-admission and hospital-discharge records from nine states dating back to 2009. The team identified 187,188 patients who landed in the hospital with a diagnosis of stroke. Then they looked back through the records of those patients to see which ones had visited the hospital’s ER within the past 30 days with symptoms that might have been those of a stroke or a TIA but were diagnosed as something else.

Of these 187,188 patients, it was discovered that 23,809—or 13%—were possibly having a stroke during their earlier ER visit, but the examination they got in the ER—or the ER physician’s suspicion that a stroke was happening—wasn’t strong enough to make a stroke diagnosis stick. I’m sure you have been in a position where a doctor needs more time and trial and error to find out what’s wrong with you…but you want a doctor to be especially thorough and on the ball now if you have a life-threatening condition! And the study found out that a more thorough approach is exactly what’s needed in the ER.


If you are not, say, a 55-year-old man—the type of person who is one of the most at risk for stroke—your stroke symptoms might be confused for something else. For example, the Johns Hopkins study revealed that women are 33% more likely to be misdiagnosed than are men. Why? Mainly because generalized symptoms, such as headache and dizziness, are naturally more common in women, and therefore are less likely to be considered possible signs of stroke.

More shocking, though…if you are black, Asian or Hispanic, your stroke symptoms might be overlooked because you didn’t receive as thorough an examination as what a white person with the same symptoms might’ve gotten. In these two ethnic groups, the risk of misdiagnosis in the ER ranged from 18% to 30%! So if you are black, Asian or Hispanic, it is especially important that you be proactive about knowing what kind of care you and family members are entitled to and making sure you receive it.

Young people have strokes, too. Although less likely to have a stroke than older people, those 18 to 45 years old were seven-fold more likely than the elderly (people age 80 and older) to be misdiagnosed when stroke was probably the true cause of their symptoms.

Another alarming finding from the study was that across all ethnic and age groups on average, if you use an ER of a nonteaching hospital—that is, a hospital that is not connected to a medical college—you face rather high odds of having a stroke missed: 45%. And, worse, if you are in a low-volume ER—meaning one that doesn’t see very many patients compared with other hospitals—the odds of being misdiagnosed increase to 57%! The take-home message here is that, if at all possible, use a busy university hospital when you need to get to an ER.


Early recognition and treatment of a stroke improves outcomes and reduces the risk of future strokes by as much as 80%. Diagnosing a stroke correctly, quickly and early is, therefore, crucial. For ways to better protect yourself against having a stroke in the first place, check out our guide to How to Prevent a Stroke.

The researchers are not recommending that every patient who comes through the ER with a headache or dizziness have a CT scan or MRI to definitively rule out a stroke—that has been proven to be a highly inefficient way to identify patients at risk for stroke, in addition to driving up health-care costs. In fact, CT scans done only a few hours after stroke symptoms begin are commonly normal, with the damage caused by stroke showing up days later. Even MRI scans miss strokes in the first 24 hours up to 20% of the time. Instead, the research team is recommending that ER doctors use proven methods to identify strokes at the patient’s bedside—get a thorough history of symptoms that have occurred over time and do a physical exam that doesn’t depend on race or age and specifically focus on symptoms (such as carefully inspecting specific eye movements if dizziness is the main symptom). And, given the high rate of misdiagnosis in black, Asian and Hispanic people, the researchers recommend that doctors be vigilant, regardless of a patient’s race, ethnicity, gender or age, so that everyone has a strong chance of a correct diagnosis. You are entitled to nothing less.