Is it possible to have a small stroke and not even realize it?

Yes, according to new research that found about 35 percent of Americans experience symptoms of a warning stroke. Yet only about 3 percent get immediate medical attention.

Most adults who had at least one sign of a “mini” stroke — a temporary blockage also known as a transient ischemic attack (TIA) — waited or rested until symptoms had faded instead of calling 911 right away, according to the research from the American Heart Association/American Stroke Association (AHA/ASA).

“Ignoring any stroke sign could be a deadly mistake,” said ASA chair Dr. Mitch Elkind, in a news release from the organization.

“Only a formal medical diagnosis with brain imaging can determine whether you’re having a TIA or a stroke. If you or someone you know experiences a stroke warning sign that comes on suddenly — whether it goes away or not — call 911 right away to improve chances of an accurate diagnosis, treatment and recovery,” he said.

An ischemic stroke occurs when a clot blocks blood flow to the brain. People who experience this type of stroke may be treated immediately with a special clot-busting drug. A device called a stent retriever may also be used to remove the clot and help prevent long-term disability.

A TIA precedes about 15 percent of strokes. People who have a TIA are at greater risk for a stroke within three months, the experts said.

The American Stroke Association uses the acronym F.A.S.T. to help people remember the most common stroke signs:

• Time to call 911.

Other sudden warnings signs of stroke include:

• Unexplained severe headache.

The survey of more than 2,000 adults found that those who suddenly experienced trouble walking, dizziness, loss of balance or coordination, or numbness or weakness in their face or a limb, were most likely to call 911. The most common symptom was a sudden, severe headache. About 1 in 5 people experienced this symptom, according to the study.

The researchers noted that 77 percent of those polled were not familiar with a TIA. More than half of the participants said they would dial 911 if they thought they or someone else had symptoms of a TIA but only 3 percent of those who did have these warning signs actually made the call.

People who’ve had a stroke or TIA must work with their doctor to make lifestyle adjustments and follow a treatment regimen to help prevent another event, the researchers said.

“Officially, about 5 million Americans, or 2.3 percent, have had a self-reported, physician-diagnosed TIA,” said Elkind. “But as this survey suggests, we suspect the true prevalence is higher because many people who experience symptoms consistent with a TIA fail to report it.”

More information

The U.S. National Stroke Association provides more information on stroke.

SOURCE: American Stroke Association, news release, May 1, 2017