Stroke

A stroke is a life-threatening condition that happens when part of your brain doesn’t have enough blood flow. This most commonly happens because of a blocked artery or bleeding in your brain. Without a steady supply of blood, the brain cells in that area start to die from a lack of oxygen.

IMPORTANT: A stroke is a life-threatening emergency condition where every second counts. If you or someone with you has symptoms of a stroke, IMMEDIATELY call 911 (or your local emergency services number). The quicker stroke is treated, the more likely you’ll recover without disability.

To recognize the warning signs of a stroke, remember to think BE FAST:

• B. Be watchful for a sudden loss of balance.
• E. Look out for sudden loss of vision in one or both eyes. Are they experiencing double vision?
• F. Ask the person to smile. Look for a droop on one or both sides of their face, which is a sign of muscle weakness or paralysis.
• A. A person having a stroke often has muscle weakness on one side. Ask them to raise their arms. If they have one-sided weakness (and didn’t have it before), one arm will stay higher while the other will sag and drop downward.
• S. Strokes often cause a person to lose their ability to speak. They might slur their speech or have trouble choosing the right words.
• T. Time is critical, so don’t wait to get help! If possible, look at your watch or a clock and remember when symptoms start. Telling a healthcare provider when symptoms started can help the provider know what treatment options are best for you.

Who does it affect?

Anybody can have a stroke, from children to adults, but there are some people who have a greater risk than others. Strokes are more common later in life (about two-thirds of strokes happen in people over age 65).

There are also certain medical conditions that increase the risk of stroke, including high blood pressure (hypertension), high cholesterol (hyperlipidemia), Type 2 diabetes, and people who have a history of stroke, heart attack or irregular heart rhythms like atrial fibrillation.

How common is a stroke?

Strokes are very common. Worldwide, strokes rank second among the top causes of death. In the United States, stroke is the fifth cause of death. Strokes are also a leading cause of disability worldwide.

How does a stroke affect my body?

Strokes are to your brain what a heart attack is to your heart. When you have a stroke, part of your brain loses its blood supply, which keeps that brain area from getting oxygen. Without oxygen, the affected brain cells become oxygen-starved and stop working properly.

If your brain cells go too long without oxygen, they’ll die. If enough brain cells in an area die, the damage becomes permanent, and you may lose the abilities that area once controlled. However, restoring blood flow may prevent that kind of damage or at least limit how severe it is. That’s why time is critical in treating a stroke.

What are the types of stroke?

There are two main ways that strokes can happen: ischemia and hemorrhage.

Ischemic stroke

Ischemia (pronounced “iss-key-me-uh”) is when cells don’t get enough blood flow to supply them with oxygen. This usually happens because something blocks blood vessels in your brain, cutting off blood flow. Ischemic strokes are the most common and account for about 80% of all strokes.

Ischemic strokes usually happen in one of the following ways:

• Formation of a clot in your brain (thrombosis).
• A fragment of a clot that formed elsewhere in your body that breaks free and travels through your blood vessels until it gets stuck in your brain (embolism).
• Small vessel blockage (lacunar stroke), which can happen when you have long-term, untreated high blood pressure (hypertension), high cholesterol (hyperlipidemia) or high blood sugar (Type 2 diabetes).
• Unknown reasons (these are cryptogenic strokes; the word “cryptogenic” means “hidden origin”).

Hemorrhagic stroke

Hemorrhagic (pronounced “hem-or-aj-ick”) strokes cause bleeding in or around your brain. This happens in one of two ways:

• Bleeding inside of your brain (intracerebral). This happens when a blood vessel inside of your brain tears or breaks open, causing bleeding that puts pressure on the surrounding brain tissue.
• Bleeding into the subarachnoid space (the space between your brain and its outer covering). The arachnoid membrane, a thin layer of tissue with a spiderweb-like pattern on it, surrounds your brain. The space between it and your brain is the subarachnoid space (“sub” means “under”). Damage to blood vessels that pass through the arachnoid membrane can cause a subarachnoid hemorrhage, which is bleeding into the subarachnoid space, putting pressure on the brain tissue underneath.