What is a stroke?
A stroke (also known as a cerebro-vascular accident) occurs when the blood supply to your brain is reduced or interrupted by a blood clot or a hemorrhage. This deprives the brain tissue of oxygen and nutrients, and causes brain cells to begin dying within a few minutes.
Stroke warning signs
The five warning signs of stroke are:
1) Sudden onset of weakness/numbness on one side
2) Sudden speech difficulty or confusion
3) Sudden visual difficulty (one or both eyes)
4) Sudden onset of dizziness, trouble walking, or loss of balance
5) Sudden, severe headache with no known cause
If you experience any of these symptoms, call 911 immediately and the ambulance will take you to the nearest emergency room.
Stroke risk factors
The following are risk factors for stroke and may be modified to lower your risk:
- High blood pressure
- Diabetes
- Atrial fibrillation (irregular heartbeat)
- Elevated cholesterol
- Being overweight
- Tobacco usage
- Heavy alcohol use
Types of stroke
Ischemic stroke: Occurs when blood vessels are blocked by a clot. The clot can be a thrombus, a clot that forms at the site of the blockage; or an embolus, a clot that has moved from another part of the body and lodged in a blood vessel that feeds the brain.
- 85% of strokes are ischemic. The most important risk factors for ischemic strokes are longstanding increased arterial blood pressure, diabetes and atrial fibrillation (irregular heart beat).
Hemorrhagic stroke: Occurs as a result of rupture or perforation of blood vessels within the brain. Hemorrhagic strokes can be caused by longstanding arterial hypertension, aneurysms (weakened blood vessel wall); trauma, drug abuse or a malformations of the blood vessel.
- Approximately 15% of all strokes are hemorhagic. The most important risk factor for these strokes is arterial hypertension.
Transient ischemic attack (TIA): Sometimes called a “mini-stroke," a TIA is a warning sign of the potential for a future stroke. A TIA may last only a few minutes, or up to 24 hours. TIA occurs when the blood supply to part of the brain is briefly interrupted. Symptoms are similar to those of stroke but do not last as long.
- About one-third of strokes are preceded by one or more TIAs that can occur days, weeks or even months before a stroke.
- If you experience a TIA, let your physician know immediately and schedule a follow-up appointment as soon as possible to discuss stroke prevention.
To schedule an appointment at the UCSD Stroke Center, call (858) 657-8540.