CVA stands for cerebrovascular accident, which is the medical term for a stroke. It happens when blood flow to part of the brain is suddenly cut off, starving brain cells of oxygen. Those cells begin dying within minutes, which is why strokes are treated as medical emergencies. The term “accident” is somewhat misleading, since most strokes result from identifiable, often preventable risk factors.
How a CVA Happens
There are two types of CVA, and they involve opposite problems with blood vessels in the brain.
Ischemic stroke accounts for about 80% of all strokes. It occurs when a blood clot blocks a vessel supplying the brain. The clot may form locally in a narrowed brain artery, or it may travel from elsewhere in the body, often the heart. Without blood flow, the tissue downstream from the blockage starts to die.
Hemorrhagic stroke makes up the remaining 20%. Here, a blood vessel in the brain ruptures and bleeds into the surrounding tissue. The bleeding itself damages cells, and the areas beyond the rupture lose their blood supply. Hemorrhagic strokes tend to be more immediately dangerous, though both types can cause lasting disability or death.
Recognizing the Signs
The acronym BE-FAST captures the most common warning signs:
- Balance: Sudden loss of coordination or difficulty walking
- Eyes: Blurred or double vision, or sudden vision loss in one or both eyes
- Face: Drooping on one side, especially noticeable when trying to smile
- Arm: Weakness or numbness in one arm (or leg)
- Speech: Slurred words, difficulty speaking, or trouble understanding others
- Time: Call emergency services immediately
The older, simpler FAST acronym misses a significant number of strokes. Among patients whose symptoms didn’t fit FAST, 40% had visual problems and 33% had gait imbalance as their primary symptom. Sudden dizziness, severe headache with no known cause, and leg weakness are also common presentations that people may not immediately associate with stroke.
CVA vs. TIA
A transient ischemic attack, or TIA, is sometimes called a “mini-stroke.” It produces the same symptoms as a CVA, but they resolve on their own, typically within an hour. The traditional cutoff was 24 hours: if symptoms lasted less than a day, it was labeled a TIA rather than a stroke.
That time-based definition has largely been replaced by a tissue-based one. Doctors now define a TIA as a temporary episode of stroke-like symptoms with no evidence of permanent brain damage on imaging. This matters because one-third of people with classically defined TIAs actually show signs of new brain injury on MRI. In other words, some events that look temporary still leave a mark. A TIA is a serious warning: it signals that the conditions for a full stroke are in place, and it often precedes one.
How a CVA Is Diagnosed
In the emergency room, a CT scan is the standard first step. It’s fast and widely available, and its main job is to determine whether the stroke is ischemic or hemorrhagic, since the treatments are very different. CT is better at detecting bleeding than it is at spotting early ischemic damage.
MRI is more sensitive for identifying ischemic strokes, pinpointing the exact location and size of the affected area, and ruling out conditions that mimic stroke. When hospitals used MRI as the first-line scan instead of CT, the rate of non-stroke patients mistakenly treated with clot-dissolving medication dropped by half (from 8.6% to 4.3%). The tradeoff is that MRI takes longer and isn’t available in every hospital, so CT remains the default in most emergency departments.
Doctors also use a standardized scoring tool called the NIH Stroke Scale to grade severity. It tests things like limb strength, speech, vision, and awareness. Scores range from 0 to 42: 0 to 5 indicates a minor stroke, 6 to 15 moderate, 16 to 20 moderate-to-severe, and 21 and above severe.
Emergency Treatment
For ischemic strokes, the primary treatment is a clot-dissolving medication given through an IV. This must be administered within 4.5 hours of symptom onset to be effective. In select cases where imaging shows brain tissue that can still be saved, the window may extend to 9 hours, including for people who wake up with stroke symptoms.
For larger clots blocking major arteries, a procedure called mechanical thrombectomy can physically remove the clot using a catheter threaded through blood vessels. This can be performed up to 24 hours after symptoms begin in eligible patients, a significantly wider window than medication alone. Not every stroke qualifies: the blockage needs to involve a large artery, and imaging must show that enough brain tissue remains viable to justify the procedure.
Hemorrhagic strokes require a different approach entirely. Clot-dissolving drugs would make the bleeding worse. Treatment focuses on controlling blood pressure, stopping the bleed, and sometimes surgical intervention to relieve pressure on the brain.
Major Risk Factors
High blood pressure is the single biggest risk factor for stroke. It damages artery walls over time, making them more prone to both clots and ruptures. Many people with high blood pressure have no symptoms, which is why routine screening matters.
Diabetes roughly doubles stroke risk, partly because high blood sugar damages blood vessels and partly because diabetes tends to travel with high blood pressure and high cholesterol. Heart conditions, particularly atrial fibrillation (an irregular heartbeat), are another major contributor. Irregular rhythms allow blood to pool in the heart and form clots that can travel to the brain.
Other significant risk factors include high cholesterol, which narrows arteries with plaque buildup; obesity, which drives up blood pressure, cholesterol, and diabetes risk; smoking, which damages blood vessels and reduces oxygen in the blood; and heavy alcohol use, which raises blood pressure and triglyceride levels. Sickle cell disease is an important cause of ischemic stroke in children, particularly Black children, because abnormally shaped red blood cells can block blood flow to the brain.
Recovery and Long-Term Outlook
Recovery after a CVA varies enormously depending on the stroke’s severity, location, and how quickly treatment was received. The most rapid improvement typically happens in the first three to six months. About 58% of patients with significant disability after a stroke improve by at least one functional level within three months, and roughly a quarter continue to show gains between 3 and 12 months.
The long-term numbers are sobering: nearly 45% of stroke survivors over age 65 have persistent moderate or severe disability. This can include difficulty walking, trouble with speech or language, problems with memory and thinking, emotional changes, and difficulty with daily activities like dressing or eating. Rehabilitation, including physical, occupational, and speech therapy, plays a central role in recovery and can continue to produce results well beyond the initial months, though the pace of improvement does slow over time.