A Transient Ischemic Attack (TIA) is as Urgent as a Stroke

If you have a sudden, unusual symptom, but it goes away, should you drop everything and seek help? If that symptom is slurred speech, weakness or numbness on one side of the body, double vision, loss of vision in one or both eyes, balance problems—or anything else that resembles a stroke—the answer is yes, absolutely. It could be a transient ischemic attack (TIA), also known as a “mini-stroke,” and you need to get immediate medical attention.

A TIA is similar to a full-blown ischemic stroke as far as its symptoms and potential cause. “Ischemic” means reduced blood flow to a part of the body. In the case of a TIA, blood flow to the brain may be diminished by a blood clot or other particles in a blood vessel. However, a TIA differs from a stroke because it’s temporary—with symptoms usually resolving within an hour, but sometimes lasting anywhere from just a few minutes to 24 hours—and it does not cause lasting brain damage.

Once the symptoms of a TIA go away, you might think the urgency has passed. But it’s still important to call 911 for an ambulance. That’s because, in some cases, what you think is a fleeting, random event will turn out to have been an actual stroke, a leading cause of disability in the United States. You may also need medication that must be administered within three hours of the onset of your symptoms (more on that below).

Even if it’s not a stroke, the risk of having a stroke in the 90 days following a TIA is as high as 17.8%, with almost half of those strokes occurring within two days after the TIA, according to a statement published in 2023 by the American Heart Association (AHA) and American Stroke Association (ASA) in the journal Stroke.

“No one will make you feel guilty about going to the emergency room for stroke symptoms,” says Adam de Havenon, MD, a Yale Medicine vascular neurologist with a specialty in stroke who has seen what can happen when people ignore stroke warning signs. “It’s not uncommon to have a person come to the emergency room with a stroke that is causing paralysis on one side of their body, and say, ‘I had these symptoms for 20 minutes two weeks ago and the same side of my body felt weak.’ That’s a missed opportunity for stroke prevention.”

Each year, at least 240,000 Americans have a TIA, according to the AHA/ASA statement, which recommended rapid evaluation of patients who are suspected of having a TIA and hospitalization for certain patients whose assessment reveals a high risk for recurrence of stroke symptoms. Risk assessments and brain imaging are recommended to help confirm that patients experienced a TIA and not an actual stroke, and to determine their future risk of stroke.

Below, Dr. de Havenon identifies specific characteristics of common TIA symptoms and describes how these symptoms are evaluated at a hospital.

TIAs are also called “mini-strokes,” “minor strokes,” or “warning strokes.” Two neurologists argued in a Journal of the American Medical Association (JAMA) editorial for calling TIAs “minor ischemic strokes” to emphasize the seriousness of the condition. Whatever you call them, TIAs are dangerous, says Dr. de Havenon, because they raise a person’s risk for a full-blown stroke.

People are at higher risk for a TIA—and a stroke—if they have atrial fibrillation (an irregular heartbeat), type 1 or type 2 diabetes, heart disease, high blood pressure (hypertension), high cholesterol, or if they smoke.

Both stroke and TIAs are characterized by symptoms that come on suddenly and can vary depending on which part of the brain is affected. Some common ones are:

• Weakness, numbness, or paralysis of an arm or leg, especially on one side of the body
• Face numbness or drooping
• Confusion or trouble speaking or understanding speech
• Dizziness
• Trouble seeing in one or both eyes
• Balance problems

“Dry eyes can cause blurry vision,” Dr. de Havenon says. “But when you truly lose vision, it’s like a curtain coming down. That’s always a sign that you should go to the emergency room, even if it gets better.”

The brief blockage to the brain’s blood supply that causes a TIA can have a variety of causes, including a blood clot that forms in an artery in the brain or one that forms elsewhere in the body, breaks loose and travels to the brain. The carotid arteries in the neck are the major blood vessels supplying blood to the brain, and fat deposits (known as atherosclerosis) can narrow these arteries and also cause blockage.

Emergency medical technicians (EMTs) are trained to assess the urgency of a situation in the ambulance, and hospital emergency departments prioritize stroke patients when they arrive, Dr. de Havenon says. “At Yale New Haven Hospital, we have a stroke code that involves rushing the patient to a dedicated room where we examine them very rapidly,” he says. “It’s not uncommon for their symptoms to resolve (signaling a TIA) by the time they get to the evaluation, but we still do a workup on them.”

A medical workup for a TIA involves gathering any information that might be helpful for diagnosis and treatment—and can help determine whether a patient should be admitted to the hospital or go home (and schedule a follow-up neurologist visit). It’s possible that some patients will be diagnosed with a condition that is very different from a TIA. “We might diagnose a migraine or that they were feeling very anxious and that led to unusual sensations,” Dr. de Havenon says.

More frequent use of magnetic resonance imaging (MRI) of the brain within 24 hours of the start of stroke symptoms has become a key approach to gathering information about neurovascular problems, he says. An MRI can identify a full-blown stroke, because it can show an injury to the brain, while a TIA does not cause damage that will be visible.

Computed tomography (CT) can help rule out other conditions and provide imaging, especially in settings where an MRI is not available.

There may be other tests as well, such as an electrocardiography to see if a heart issue is contributing to the symptoms; carotid ultrasonography to check for a narrowed carotid artery; and bloodwork to check for such issues as low blood sugar, which can cause symptoms that can mimic stroke.

If your diagnosis is a TIA, a medical evaluation can help determine whether and how best to treat it to prevent a full-blown stroke later on. “We will do other tests to try to understand a patient’s risk of future stroke and what treatments will lower their risk,” Dr. de Havenon says.

For example, a risk stratification instrument can show the probability that someone who has had a TIA is likely to have a stroke. One such tool is the ABCD² Score, which provides a quick score to help predict the risk of stroke in the first two days after a TIA. This system is based on a patient’s age, the nature and duration of their TIA symptoms, and whether they have a condition such as diabetes that increases their stroke risk, among other factors.

Treatment of the TIA also prevents stroke in some cases. This includes antiplatelet medications, such as aspirin or clopidogrel (Plavix®), that prevent blood clots from forming. Anticoagulant medications, such as warfarin (Coumadin®) or apixaban (Eliquis^®) also known as “blood thinners,” interfere with and slow down the clotting process.

In addition, it’s important to address diabetes, hypertension, and other stroke risk factors with medication and, in many cases, lifestyle changes. “Many of the things (such as poor diet, obesity, and sedentary lifestyle) that lead to an elevated risk for TIA and stroke also put people at higher risk for these other conditions,” Dr. de Havenon says. “Sometimes a mini-stroke is a person’s first sign that they have one of these issues.”

A person who smokes should quit, especially if they have had a TIA, Dr. de Havenon says. Lifestyle changes such as following a heart-healthy diet and avoiding alcohol will also help reduce the risk of a major stroke, he says.

How you are diagnosed and treated for a TIA could vary depending on where you live, since not every hospital has a neurologist who specializes in stroke on staff 24/7. Some hospitals do have “telestroke” programs where a stroke specialist working from central hospital can guide doctors treating TIAs and strokes at a remote location. Yale Medicine’s Stroke Telemedicine Program allows local providers at other Connecticut and Rhode Island hospitals to consult with Yale neurologists via video- and image-sharing technology.

The AHA/ASA scientific statement notes that an early consult with a neurologist following a TIA has been associated with lower 90-day and one-year mortality rates. Dr. de Havenon recommends that any TIA patient who doesn’t see a neurologist at the hospital schedule a visit with one within a week if possible.

But the most important point for people to remember is that they need to go to the emergency room when they first notice symptoms, Dr. de Havenon says. That’s because when you first have symptoms, there is no way to know whether you are having a TIA or a major stroke that is just beginning, he explains.

“If it’s a stroke, it can worsen with time,” he says. For example, if a person has a little trouble moving their right arm, 20 minutes later that arm could be paralyzed. A key treatment for stroke is tissue plasminogen activator (tPA), an FDA-approved intravenous medication that dissolves clots for someone who is having an ischemic stroke. It must be given within three hours of the onset of symptoms to restore blood flow to the brain and help prevent long-term disability.

“We will always tell you that if you are having any of these symptoms, you should come to the emergency room and be evaluated," Dr. de Havenon says.

The American Stroke Association advises calling 911 immediately if you or someone else is experiencing signs of a stroke or TIA, even if symptoms resolve within an hour. It can help to remember the acronym F.A.S.T., which stands for Face drooping or twisting, Arm weakness, Speech difficulty, and Time to call 911. The Centers for Disease Control and Prevention (CDC) strongly advises calling an ambulance and not driving yourself or letting someone else drive you to the hospital if you suspect a stroke.