Stroke on the left side: effects, treatment and recovery

A stroke occurs when a lack of blood supply or bleeding damages an area of ​​the brain. Strokes in different parts of the brain cause different symptoms. A left side stroke is a stroke that damages the left side of the brain. This type of stroke usually causes problems with language and speech, as well as physical symptoms that affect the right side of the body.

This article will discuss the types of stroke, signs, effects, treatment and prevention.

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Types of stroke

Most of the time, strokes are caused by not having enough blood supply to an area of ​​the brain. Ischemia is a lack of blood supply due to a blockage or narrowing of a blood vessel.

Sometimes a stroke can occur due to a hemorrhage (bleeding) often caused by a leaky blood vessel.


An ischemic stroke causes damage to an area of ​​the brain that is supplied by the blood vessel that is blocked (blocked).

This type of stroke can occur due to atherosclerotic disease in the blood vessels in the brain (hardening and narrowing due to a build-up of cholesterol plaques). Changes in blood vessels leading to narrowing and ischemic stroke can also be caused by high blood pressure, diabetes, and smoking.

Ischemic strokes can also occur due to a blood clot traveling to the brain from the heart or a blood vessel further away.


A hemorrhagic stroke can occur due to a ruptured brain aneurysm (a bulging area in the wall of an artery), a damaged leaking blood vessel, or damage from an ischemic stroke.

A hemorrhagic stroke can cause tissue death (infarction) in the area of ​​the brain that is supplied by the bleeding blood vessel. In addition, the accumulation of blood can cause further damage to nearby areas.

Brain damage from a hemorrhagic stroke can lead to seizures (uncontrolled electrical disturbances in the brain) due to the irritation caused by the bleeding. In some people, seizures may persist even after the blood has completely reabsorbed. This most often happens when blood affects an area of ​​the brain that controls motor function.

Signs of stroke

There are several signs of a stroke on the left side. They include:

  • Weakness of the face, arm and / or lower leg on the right side of the body
  • Decreased sensation on the right side of the body
  • Laborious or muddled speech
  • Speak fluently but with incorrect content or without words
  • Difficulty understanding the language
  • Changes in visual perception
  • Sudden severe headache
  • Sudden dizziness or loss of balance
  • Confusion
  • Sensory and motor symptoms on the left side if the stroke affects areas known as the cerebellum and brainstem

See a doctor immediately if you or someone else experiences any of these symptoms. A stroke is a medical emergency that can quickly get worse, resulting in disability or death. Long-term effects can be minimized if treatment is started early.


The lasting effects of a left side stroke range from mild to severe, depending on the size of the stroke and the time of treatment.

Hemiplegia and hemiparesis on the right side

Hemiplegia and hemiparesis can occur on the right side of the body after a stroke on the left side, which are:

  • Hemiplegia is complete paralysis, and it can affect the right side of the face, arm, and / or leg after a left-sided stroke.
  • Hemiparesis is partial weakness with some residual strength.

Immediately after a stroke on the left side, hemiplegia or hemiparesis of the right body will be apparent. After months or more, weak areas of the body can gradually become stronger and better coordinated. People with moderate to severe weakness are more likely to experience spasticity, with stiffness and stiffness in the muscles.

Decreased sensation on the right side

Diminished sensation on the right side of the body may occur after a stroke involving the left sensory cortex or the left internal capsule. The decreased sensation can involve the face, arm and / or leg, and sometimes the torso.

Sensory impairment can indirectly affect your ability to control your body, as you rely on sensory feedback to coordinate your movements.

In addition to a decrease in sensation, paresthesias can sometimes occur in the same areas that have a decrease in sensation. Paresthesias involve numbness, tingling, burning, or a feeling of pins and needles. They can occur when the specific area of ​​the body is affected or without a trigger.


Strokes on the left side are known to cause aphasia, which is a language deficit. There are several types of aphasia, and they occur when one or more areas of speech in the brain are damaged.

Wernicke’s aphasia, also called fluid aphasia, causes difficulty understanding language. A person with this type of aphasia can speak fluently, but the words don’t make sense. Wernicke’s aphasia can occur when there is damage to the area of ​​language near the left sensory cortex of the brain.

Broca’s aphasia is a type of language deficit in which a person may have full or slightly impaired speech understanding, with difficulty forming words and sentences. This type of aphasia occurs when there is damage to the area of ​​speech near the left motor cortex of the brain.

Language centers

Aphasia occurs when the language areas of the brain are damaged. Language is usually located in the left hemisphere of the brain. For almost all right-handed people, language functions are located on the left side of the brain. Some left-handed people have the language centers on the right side of the brain.

Apraxia of speech

Word apraxia is a difficulty with the brain’s control of motor speech movements. Unlike dysphagia, which is not specific to lesions on one side of the brain and affects speech and swallowing, apraxia of speech is a type of language disorder.

Apraxia of speech can begin in childhood due to developmental conditions, or it can occur as a result of damage to the left insular cortex, an area deep in the left hemisphere of the brain.

Cognitive impairments

After a stroke affecting the left hemisphere of the brain, a person may develop difficulty in thinking and making decisions. These cognitive deficits, often described as executive dysfunction, can occur due to damage to the left frontal lobe, left temporal lobe, or left parietal lobe. Generally, a larger stroke should lead to more severe cognitive impairment.

Homonymous hemianopia

After a left-sided stroke involving the temporal lobe, parietal lobe, or occipital cortex at the back of the brain, a person may have vision defects on the right side. Hemianopia of the same name as a left-sided stroke is loss of vision in the right visual field of both eyes. It can affect the upper or lower field of vision or both.


A stroke should be treated immediately after the onset of symptoms. It is important to request emergency transport to the hospital for prompt and proper medical attention on arrival.

Treatment may include blood thinners, blood pressure control, and fluid management. Sometimes an interventional procedure may be needed to remove a blood clot or to relieve pressure in the skull. Advanced emergency department imaging may be needed to help decide the risks and benefits of any potential intervention.

Once your condition has stabilized, treatment focuses on recovery and rehabilitation. Physical therapy and occupational therapy can help improve your motor control and make you as independent and physically capable as possible.

After stroke, patients who qualify and complete an intensive / acute rehabilitation course may have better outcomes and lower mortality (death rate) than those who do not receive such care.

Additionally, speech therapy is often required for the safe management of aphasia, cognitive difficulties, and swallowing limitations. Any neurological rehabilitation takes time but can significantly help a person improve their ability to communicate with others and to function independently.


Prevention of stroke is a comprehensive strategy to reduce the risk of cerebrovascular disease. Prevention involves drug, diet, and lifestyle approaches.

Prevention of stroke includes:

  • Smoking cessation
  • Control of cholesterol and triglycerides
  • Blood pressure control
  • Blood sugar control
  • Management of heart disease, including abnormal heart rhythms such as atrial fibrillation

After a stroke, these problems need to be treated long term.


A left side stroke usually affects the left side of the brain and the right side of the body. This type of stroke can also cause cognitive and language problems, which can include difficulty in understanding, speaking, or both.

Stroke is a medical emergency, and immediate treatment can help prevent disability or death. Recovery from a stroke on the left side involves physical rehabilitation, as well as speech therapy.

A word from Verywell

A stroke on the left side can be life changing. This can lead to weakness and communication problems that interfere with your ability to live your life the way you did before the stroke. These potential effects have a major impact on stroke survivors and their loved ones.

Get help after a stroke to get the help you need to recover. It can take time and hard work, but it’s important to be patient and maintain a bond. Friends and family can help greatly by learning about the effects of a left-sided stroke and changing expectations, especially when it comes to communication.

Frequently Asked Questions

  • How common are strokes on the left side?

    Strokes on the left side occur about as frequently as strokes on the right side. According to the Centers for Disease Control and Prevention (CDC), each year more than 795,000 people in the United States suffer from stroke.

  • Which side of the brain is worse for having a stroke?

    The effects of a stroke on either side of the brain can range from mild to disabling. After a stroke on the left side, language can be a big problem, and after a stroke on the right side, neglect on the left side of the body can be a big problem.

  • How long does it take to recover from a stroke on the left side?

    It depends on the severity of the stroke and the amount of damage caused. It may take months or more to improve after a stroke. A person can recover almost completely or may have significant permanent disabilities after a stroke.

About Antoine L. Cassell

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