Difference Between a Heart Attack and Stroke

Defect of the blood-brain barrier after stroke shown in MRI. T1-weighted images, left image without right image with contrast medium administration.
Hellerhoff/Wikimedia Commons

When you are learning about CPR and first aid, it is important to know the differences between heart attack and stroke. These are two very different medical emergencies. Both develop from blockages in the blood vessels but affect different critical functions of the body.

Heart Attack

A heart attack refers to damage to the muscle of the heart, usually from a lack of blood flow. Most of the time, a blood clot forms in one of the arteries that supply the heart muscle, blocking the flow of blood that it needs to nourish it. As the heart muscle starves, it begins to die. This causes chest pain and other heart attack symptoms.

The term heart attack is self-explanatory. But a heart attack is the layperson's term for an acute myocardial infarction (AMI) or an acute coronary syndrome (ACS). They aren't exactly the same, but the first aid treatment is the same for both types of a heart attack.

Before someone experiences a heart attack, he could have symptoms of a heart attack that go away even without treatment. A narrowing of an artery leading to the heart muscle can cause what's known as angina.


A stroke is also a blockage, usually a blood clot, in an artery that supplies blood to the brain. When a clot forms in one of those arteries and stops blood flow, a section of the brain begins to die. Stroke symptoms often don't include any pain or discomfort. A stroke is more likely to be associated with losing feeling or the ability to move. Much of the time, strokes affect only one side of the body.

Strokes come in three forms.

  • A stroke caused by a blood clot is known as an ischemic stroke.
  • Bleeding in the brain—most likely from an aneurysm—is called a hemorrhagic stroke.
  • transient ischemic attack is a narrowing of an artery that feeds blood to the brain. The narrow part of the blood vessel restricts blood so much that stroke symptoms can happen for a short time and then go away. That's why it's called transient.

Stroke is a puzzling term. Some say it is short for "stroke of God" and refers to the immediate and devastating effects of that blood clot in the brain. Some in the medical community are attempting to do away with the term stroke and replace it with brain attack. This change is difficult to make, and there is already a term with the word attack in it that refers to a type of stroke.

The Bottom Line

A heart attack is a blockage of an artery in the heart that leads to a damaged heart muscle unless it goes away on its own without treatment. In that case, it's angina.

A stroke is a blockage of an artery that goes to the brain, which some people like to call a brain attack—not to be confused with the version that resolves all by itself and is already called a transient ischemic attack.

Learning the symptoms of these conditions is important so it can be recognized and treated as soon as possible. If you have symptoms of a heart attack or a stroke, call 911.

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