A CVA, or cerebrovascular accident, is the medical term for a stroke. It happens when blood flow to part of the brain is suddenly cut off or when a blood vessel in the brain bursts, killing brain cells within minutes. Globally, nearly 12 million people have a new stroke each year, and stroke is the second leading cause of death worldwide.
Two Main Types of CVA
Strokes fall into two broad categories based on what goes wrong with the blood supply to the brain.
Ischemic stroke accounts for about 87% of all strokes. It occurs when a clot or fatty deposit blocks an artery feeding the brain. The blockage can form locally inside a narrowed brain artery, or it can travel from somewhere else in the body, often the heart. The most common subtypes include clots caused by heart rhythm problems (about 38% of ischemic strokes), blockages from fatty buildup in large arteries (16%), and disease in the brain’s smallest blood vessels (11%).
Hemorrhagic stroke makes up the remaining 13%. It happens when a weakened blood vessel ruptures and bleeds into or around the brain. About 10% of all strokes involve bleeding directly into brain tissue, while roughly 3% result from a burst aneurysm that bleeds into the space surrounding the brain. Hemorrhagic strokes tend to be more immediately dangerous, but both types can cause severe, lasting damage.
How a TIA Differs From a Full Stroke
A transient ischemic attack, sometimes called a “mini-stroke,” produces the same symptoms as a full CVA but does not permanently damage brain tissue. A TIA typically lasts less than an hour, often only minutes, and resolves on its own once blood flow is restored. The modern medical definition focuses on whether brain tissue was actually injured (visible on imaging), not simply on how long symptoms lasted. A TIA is a medical emergency because it signals that a full stroke may follow soon.
Key Risk Factors
High blood pressure is the single biggest controllable risk factor. It is present in roughly 77% of people experiencing their first stroke. High blood pressure damages artery walls over time, making them more prone to clots and rupture.
Atrial fibrillation, an irregular heart rhythm, is another major driver. People with atrial fibrillation face about 3.2 times the risk of a clot-related stroke compared to those with a normal rhythm. When atrial fibrillation and high blood pressure occur together, the risk of stroke jumps an additional two to three times beyond either condition alone. Controlling blood pressure in people with atrial fibrillation is one of the most effective ways to lower stroke risk.
Other well-established risk factors include diabetes, smoking, high cholesterol, obesity, and heavy alcohol use. Non-modifiable risks include age, family history, and having had a previous stroke or TIA.
Recognizing a Stroke: The BE FAST Signs
Speed matters enormously during a stroke. Every minute without treatment, more brain tissue dies. The BE FAST acronym helps you spot the warning signs:
- B, Balance: sudden loss of balance or coordination
- E, Eyes: sudden vision loss in one or both eyes, or new double vision
- F, Face: one side of the face droops, especially when trying to smile
- A, Arms: sudden weakness in one arm or leg, often on just one side of the body
- S, Speech: slurred words, difficulty speaking, or trouble understanding others
- T, Time: call 911 immediately
Symptoms can appear in any combination. Some people experience only one, while others have several at once. Even if symptoms seem to improve on their own, that pattern may indicate a TIA, which still requires urgent evaluation.
How a Stroke Is Diagnosed
The first step in the emergency department is almost always a non-contrast CT scan of the head. This scan is fast and highly reliable at detecting bleeding in the brain, which is critical because treatment for an ischemic stroke (dissolving or removing a clot) would be dangerous if the stroke is actually hemorrhagic. CT is extremely accurate at ruling out bleeding, though it can miss early signs of an ischemic stroke in the first few hours.
If doctors suspect a large clot that might be removed with a catheter-based procedure, they typically add a CT angiogram to map the blood vessels and locate the blockage. This imaging is 97% to 100% sensitive at detecting blocked or narrowed arteries in the brain. MRI provides the most detailed picture of brain tissue damage and is the preferred tool for evaluating TIAs and strokes diagnosed outside the initial treatment window.
The Recovery Timeline
Rehabilitation typically begins within 24 hours of the stroke being treated, while the patient is still in the hospital. The average hospital stay is five to seven days, during which therapy sessions may happen up to six times a day. These early sessions help clinicians assess the extent of the damage and start rebuilding skills immediately.
The first three months are the most critical window for recovery. During this period, the brain is especially capable of reorganizing itself, a process called neuroplasticity. Some patients experience spontaneous recovery, where an ability that seemed lost, like moving a hand or forming a sentence, returns suddenly as the brain recruits new pathways to take over for damaged areas. After six months, improvement is still possible but generally slows significantly, and most patients reach a relatively stable level of function.
Rehabilitation often involves physical therapy (for movement and balance), occupational therapy (for daily tasks like dressing and eating), and speech therapy (for language and swallowing problems). One newer approach uses weak electrical currents applied to the scalp to stimulate brain regions involved in movement or speech, which can amplify the benefits of traditional therapy.
Long-Term Effects
A stroke can affect nearly every aspect of daily life, depending on which part of the brain was damaged and how severely. Physical effects commonly include weakness or paralysis on one side of the body, increased muscle stiffness, and sensory changes like numbness or tingling. Many survivors struggle with aphasia, a difficulty producing or understanding language that occurs when the brain’s language centers are damaged.
Cognitive effects are surprisingly common. Over 50% of stroke survivors develop some degree of cognitive impairment, ranging from trouble with memory and concentration to difficulty planning and problem-solving. About 10% develop dementia after a first stroke, and that figure climbs to over one-third after a recurrent stroke.
Depression is the most frequent psychiatric complication. Roughly one in three stroke survivors experiences depression within the first year, driven by both the emotional weight of disability and direct changes to brain chemistry caused by the stroke itself. This rate decreases to about 25% after the first year but remains well above the general population. Post-stroke depression can slow physical recovery if untreated, making it important to address alongside physical rehabilitation.