Left vs. right side: Why the location of a stroke matters

You may have heard of the B.E. F.A.S.T. acronym, a simple way to recognize a stroke quickly: loss of balance, (eye) vision changes, face drooping, arm weakness, speech difficulties, time to call 911. But not all strokes look the same, and they aren’t always easy to recognize. Symptoms can vary depending on whether a stroke occurs on the left or right side of the brain.

Why strokes can look different

The brain works in a crossed pattern. The right side controls the left side of the body, and the left side controls the right. Each side also has different roles. For most people, the left side of the brain is more involved in language and communication, while the right side plays a key role in awareness and spatial perception.

“Depending on which part of the brain is affected, a person may experience different stroke symptoms,” says Dr. Deepa Bhupali, the stroke program medical director at Advocate Health Care.

A stroke on the left side of the brain often affects language, making it difficult to speak, understand words or name objects. A stroke on the right side of the brain often affects spatial awareness. Patients may not notice these changes themselves, which can make it harder to recognize symptoms and seek timely care.

Why stroke symptoms can be easy to miss

“Stroke symptoms aren’t always obvious,” says Dr. Bhupali. “Some patients don’t realize anything is wrong until someone else notices.”

Dr. Bhupali recalls a young patient who believed his slurred speech and unsteadiness were due to drinking, when in fact he was having a stroke. In another case, a patient insisted they felt fine, even as they repeatedly bumped into objects on one side and only ate food from one side of the plate. A family member recognized the change and sought care.

Another misconception Dr. Bhupali often hears is that strokes are painful. Unlike a heart attack, which often causes chest pain, stroke symptoms are actually often painless and, therefore, are sometimes dismissed or attributed to something else. Because stroke symptoms can vary widely and often don’t match what people expect, they can be easy to miss.

Why recovery isn’t the same for everyone

The side of the brain affected doesn’t determine how severe the stroke is, but it does shape the challenges one may face.

“Recovery after a stroke is different for every patient, but the location of the stroke can influence both the challenges they face and the type of therapy that might be most beneficial,” says Dr. Bhupali.

Left-sided strokes often affect speech and language. Recovery may include speech therapy to help patients regain communication skills. This can be frustrating, especially when patients know what they want to say but are unable to express it.

Right-sided strokes can affect awareness and spatial recognition. Patients may need therapy focused on balance, coordination and learning to navigate their environment more safely.

Recognizing stroke and acting quickly

Recognizing the signs of stroke and acting quickly can make a critical difference. Even though symptoms can vary, the B.E. F.A.S.T. acronym captures the most common signs to watch for.

“The sooner someone gets to the emergency room, the more treatment options they have,” says Dr. Bhupali. “If you think someone may be having a stroke, call 911. Even if you’re wrong, it’s better to be evaluated than to wait.”

Want to learn more about your risk for stroke? Take a free online quiz.