Many Americans are somewhat aware of stroke symptoms.
While early action is crucial for improving outcomes, healthcare experts highlight the importance of stroke prevention. According to the Stroke Foundation, understanding the triggers for this serious medical event is essential—it’s the fifth leading cause of death in the U.S.
The American Heart Association defines a stroke as occurring when blood vessels either rupture in the brain (known as a hemorrhagic stroke) or become blocked by a clot (termed ischemic stroke). Such events inhibit oxygen flow, causing brain cells to deteriorate.
But, what exactly leads to these conditions that culminate in a stroke?
Ischemic Stroke
Atherosclerosis is primarily responsible for ischemic strokes, which make up about 87% of all cases. This condition involves the accumulation of fatty deposits, or plaques, that obstruct the walls of blood vessels.
Two scenarios arise from atherosclerosis.
Cerebral thrombosis happens when blood flow is obstructed right where a blockage occurs in the brain, inhibiting oxygenated blood flow.
On the other hand, a brain embolism occurs when a clot develops in a major artery—often in the heart or another body location—and fragments detach, traveling through blood vessels until they become lodged in a narrower passage, restricting blood flow.
Irregular heartbeat, particularly a condition known as atrial fibrillation (afib), is a main contributor to these embolisms. Afib, which affects around 5 million people in the U.S., is the most common type of irregular heartbeat.
Hemorrhagic Stroke
Hemorrhagic strokes, which account for about 13% of all strokes, result from weakened blood vessels that lead to bleeding within the brain tissue. This accumulation of blood exerts pressure on parts of the brain, further obstructing blood flow.
As noted by the AHA, hemorrhagic strokes can involve two forms of bleeding: intracerebral hemorrhage, where bleeding occurs within the brain itself, and terminal hemorrhage, which takes place between layers of brain tissue.
The typical culprits for these types of strokes include cerebral aneurysms and arteriovenous malformations.
Cerebral aneurysms are weak spots in blood vessels that gradually enlarge, resembling a balloon. When they burst, surrounding tissue bleeds. These can occur at any age but are especially common among individuals aged 30 to 60, mainly at artery junctions.
Various risk factors contribute, such as high blood pressure, smoking, drug use, infections, and head injuries.
Arteriovenous malformations are tangled blood vessels that disrupt oxygen circulation within the body. Normally, arteries deliver oxygenated blood, while veins return depleted blood to the heart and lungs. However, in the case of malformations, blood can bypass brain tissue, flowing directly from arteries to veins, complicating circulation further.
TIAs
A transient ischemic attack (TIA) is another situation alongside ischemic and hemorrhagic strokes. According to the AHA, a TIA involves a temporary blockage that usually dissolves within just a few minutes.
Even though TIAs don’t result in lasting damage, health experts warn they can signal an impending major stroke.
Like other strokes, TIA risk factors include afib, high blood pressure, diabetes, heart disease, and smoking.
Cryogenic Stroke
A cryptogenic stroke denotes a stroke where the cause remains unidentified. The AHA indicates that about one-third of ischemic strokes fall into this category.
Possible hidden triggers might include undiagnosed issues like afib, blood clotting disorders, arterial stiffness, or structural heart problems.
No matter the reasons behind a stroke, the Stroke Foundation estimates that around 80% are preventable. The crux of prevention lies in managing certain medical conditions, notably high blood pressure, high cholesterol, diabetes, and specific heart diseases.
Adopting a balanced diet low in saturated fats can aid in preventing or controlling these conditions. Regular exercise is equally vital for maintaining heart health and regulating blood pressure and cholesterol levels. Smokers face double the stroke risk compared to non-smokers and should consult their healthcare provider about quitting. Additionally, alcohol consumption, which can elevate blood pressure, should be kept moderate.
