What is a Stroke? - Causes, Symptoms & Treatment

Instructor: John Williams
A stroke is a reduction in blood flow to the brain. It is a major condition that can have devastating effects within the body. This article will address the symptoms that are experienced by patients as well as the causes of and treatments for strokes.


The brain is one of the most important organs in the human body. It serves as a control center for almost all of the systems in the body. In order for it to receive the nutrients and oxygen it needs to function, the cardiovascular system (heart and blood vessels) delivers blood to areas around the brain. This constant flow of blood plays a major role in the health of this vital organ.

So what happens if blood flow to the brain is reduced? This article will address this scenario and look at ways in which it affects the brain and the rest of the body.

What Is a Stroke?

A stroke, also known as a 'brain attack', is a reduction or disturbance in blood flow to the brain. As mentioned earlier, blood contains nutrients and oxygen that is required for the brain to function. Additionally, blood is responsible for removing waste materials that are produced by the brain during activity. A lack of blood flow during a stroke prevents both of these processes from taking place. As a result, a stroke can lead to a loss of brain cells and tissues as cells begin to die from these conditions.

Stroke Formed by a Blood Clot

Two Types of Stroke

Strokes come in two basic forms: ischemic and hemorrhagic. Ischemic stroke is a stroke where blood vessels are blocked. Typically, this comes from blood clots that lodge in the narrow vessels near the brain. Ischemic strokes can occur in several ways, including:

• Increased cholesterol (a type of lipid) in the blood vessels

• Increased blood clots migrating to the brain

• Narrowing of blood vessels (typically due to disease or chemicals, such as nicotine)

Hemorrhagic strokes occur when blood vessels become weak and break, which causes blood to leak from the circulatory system and into the brain. (As a side note, the brain does not come in direct contact with blood, but uses another fluid, called cerebrospinal fluid, to interact with blood for nutrient and gas exchange). This type of stroke is more likely in individuals who have other conditions, such as blood vessel malformation.

Risk Factors

Certain risk factors contribute to the likelihood of a stroke occurring. First, obesity (being overweight) and related illnesses can increase the chance of having a stroke. Diet, additionally, can affect this chance, particularly if a person has a diet high in fat and cholesterol. Drug usage, such as cocaine and nicotine usage, can increase the chances of a stroke due to constriction (narrowing) of blood vessels. Finally, birth control medications may increase the chance of stroke in women, particularly women over 35 years of age.


Individuals who have suffered a stroke may have a wide variety of symptoms. The types of symptoms that are present will be based on which portion of the brain is affected. One of the most common symptoms is a headache, which happens in almost all cases of stroke, even if it is mild. If the stroke happens in the area around the cerebrum, which is the portion of the brain that contains sensory and thinking abilities, then individuals may lose the ability to hear or speak, or they may appear to be confused. The cerebrum also houses motor (movement) centers, so a stroke in this area may lead to a loss of the ability to walk or move certain muscles.

The cerebellum, which primarily controls balance and coordination, can also be affected by a stroke. In this case, individuals may appear wobbly or lack the strength to walk and move properly. This is slightly different from the effects mentioned in the cerebrum in that this usually doesn't stop movement, but can impair it through a lack of coordination.

Other symptoms that may occur during a stroke include personality changes, loss of the ability to write, inability to understand language, and impairments of many other functions.

Treatment of Strokes

Stroke patients may receive many different types of treatment in order to reduce or eliminate the effects. The most critical factor in how effective the treatment will be is the time it takes for a person suffering a stroke to receive care. Stroke patients are often given blood thinners, such as heparin and warfarin, to reduce and break up blood clots. Additionally, surgeries are often performed to correct damaged blood flow and restore proper blood supplies to the brain.

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