A stroke occurs when the blood supply to part of your brain is interrupted or reduced, preventing brain tissue from getting oxygen and nutrients. Brain cells begin to die in minutes.
A stroke is a medical emergency, and prompt treatment is crucial. Early action can reduce brain damage and other complication
Symptoms of a stroke
The main symptoms of stroke can be remembered with the word FAST:
- Face – the face may have dropped on 1 side, the person may not be able to smile, or their mouth or eye may have dropped.
- Arms – the person with suspected stroke may not be able to lift both arms and keep them there because of weakness or numbness in 1 arm.
- Speech – their speech may be slurred or garbled, or the person may not be able to talk at all despite appearing to be awake; they may also have problems understanding what you’re saying to them.
- Time – it’s time to dial 112 immediately if you see any of these signs or symptoms.
There are two main causes of stroke: a blocked artery (ischemic stroke) or leaking or bursting of a blood vessel (hemorrhagic stroke). Some people may have only a temporary disruption of blood flow to the brain, known as a transient ischemic attack (TIA), that doesn’t cause lasting symptoms.
This is the most common type of stroke. It happens when the brain’s blood vessels become narrowed or blocked, causing severely reduced blood flow (ischemia). Blocked or narrowed blood vessels are caused by fatty deposits that build up in blood vessels or by blood clots or other debris that travel through your bloodstream and lodge in the blood vessels in your brain.
Hemorrhagic stroke occurs when a blood vessel in your brain leaks or ruptures. Brain hemorrhages can result from many conditions that affect your blood vessels. Factors related to hemorrhagic stroke include:
- Uncontrolled high blood pressure
- Overtreatment with blood thinners (anticoagulants)
- Bulges at weak spots in your blood vessel walls (aneurysms)
- Trauma (such as a car accident)
- Protein deposits in blood vessel walls that lead to weakness in the vessel wall (cerebral amyloid angiopathy)
- Ischemic stroke leading to hemorrhage
A less common cause of bleeding in the brain is the rupture of an abnormal tangle of thin-walled blood vessels (arteriovenous malformation).
Transient ischemic attack (TIA)
A transient ischemic attack (TIA) — sometimes known as a ministroke — is a temporary period of symptoms similar to those you’d have in a stroke. A TIA doesn’t cause permanent damage. They’re caused by a temporary decrease in blood supply to part of your brain, which may last as little as five minutes.
Like an ischemic stroke, a TIA occurs when a clot or debris reduces or blocks blood flow to part of your nervous system.
Many factors can increase your stroke risk. Potentially treatable stroke risk factors include:
Lifestyle risk factors
- Being overweight or obese
- Physical inactivity
- Heavy or binge drinking
- Use of illegal drugs such as cocaine and methamphetamine
Medical risk factors
- High blood pressure
- Cigarette smoking or secondhand smoke exposure
- High cholesterol
- Obstructive sleep apnea
- Cardiovascular disease, including heart failure, heart defects, heart infection or abnormal heart rhythm, such as atrial fibrillation
- Personal or family history of stroke, heart attack or transient ischemic attack
- COVID-19 infection
Other factors associated with a higher risk of stroke include:
- Age — People age 55 or older have a higher risk of stroke than do younger people.
- Race — African Americans have a higher risk of stroke than do people of other races.
- Sex — Men have a higher risk of stroke than women. Women are usually older when they have strokes, and they’re more likely to die of strokes than are men.
- Hormones — Use of birth control pills or hormone therapies that include estrogen increases risk.
A stroke can sometimes cause temporary or permanent disabilities, depending on how long the brain lacks blood flow and which part was affected. Complications may include:
- Paralysis or loss of muscle movement. You may become paralyzed on one side of your body, or lose control of certain muscles, such as those on one side of your face or one arm.
- Difficulty talking or swallowing. A stroke might affect control of the muscles in your mouth and throat, making it difficult for you to talk clearly, swallow or eat. You also may have difficulty with language, including speaking or understanding speech, reading, or writing.
- Memory loss or thinking difficulties. Many people who have had strokes experience some memory loss. Others may have difficulty thinking, reasoning, making judgments and understanding concepts.
- Emotional problems. People who have had strokes may have more difficulty controlling their emotions, or they may develop depression.
- Pain. Pain, numbness or other unusual sensations may occur in the parts of the body affected by stroke. For example, if a stroke causes you to lose feeling in your left arm, you may develop an uncomfortable tingling sensation in that arm.
- Changes in behavior and self-care ability. People who have had strokes may become more withdrawn. They may need help with grooming and daily chores.