Strokes are caused primarily by problems that disrupt blood flow to the brain. There are two main types of strokes:
- Ischemic stroke: This is the most common type, caused by a blockage in an artery supplying blood to the brain. The blockage is often due to a blood clot or narrowing of the artery from fatty deposits (atherosclerosis). This blockage cuts off oxygen-rich blood, causing brain cells to die
- Hemorrhagic stroke: This occurs when a blood vessel in the brain bursts or leaks, leading to bleeding inside the brain. High blood pressure is a major contributor to weakening blood vessels, making them prone to rupture. Poor blood clotting and abnormalities in blood vessel structure can also cause hemorrhagic strokes
There is also a transient ischemic attack (TIA), or "mini stroke," which is a temporary blockage of blood flow that does not cause permanent damage but signals a higher risk of a full stroke later
. Key risk factors and causes that increase the likelihood of stroke include:
- High blood pressure (hypertension), the leading cause of stroke
- Diabetes, which damages blood vessels and often coexists with high blood pressure and obesity
- Heart conditions such as atrial fibrillation (irregular heartbeat) and heart disease, which can cause clots to form and travel to the brain
- Smoking and tobacco use, which raise blood pressure and promote clot formation
- High cholesterol and atherosclerosis, which narrow arteries and promote clot formation
- Obesity and physical inactivity, which increase stroke risk through multiple pathways
- Certain medications, including blood thinners and hormone therapies, can increase bleeding risk or clot formation
- Age, family history, gender, and race also influence stroke risk, with older age and certain ethnicities having higher risk
In summary, strokes are caused by either blockage or bleeding in brain blood vessels, with high blood pressure, heart disease, diabetes, smoking, and lifestyle factors being major contributors
