Hemiplegia and Hemiparesis

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In general, paralysis means weakness of one or more parts of the body. Hemiplegia and hemiparesis are terms used to describe weakness on one side of the body.

If you have had a medical problem that has caused part of your body to become weak, you may have paralysis, paresis, hemiparesis or hemiplegia. Hemiplegia and hemiparesis are the terms used to describe weakness that affects one side of the body. For example, hemiplegia can affect the leg and arm on the same side of the body.

A physical therapist working with her patient
Dougal Waters / Digital Vision / Getty Images

Hemiplegia and paralysis mean that the affected parts of the body are completely weak, while hemiparesis and paresis mean that the affected parts of the body are only partially weak and that there is some motor strength remaining in the weakened arm or leg.


The reason for this pattern of weakness that often only affects half of the body is that the human brain and the spinal cord each have 2 identical 'halves' on the right and the left side. Each of these halves controls the movement of only one side of the body.

The human brain contains a motor region called the motor strip that controls movement. The left and right side of the cerebral cortex each contain a motor strip that controls the opposite side of the body. Similarly, the spinal cord contains a region called the corticobulbar tract that controls physical movements, with the left side controlling one side of the body and the right side controlling the other.

Thus, an injury to one side of the brain or spinal cord produces left-sided hemiplegia, while and injury to the other side produces right-sided hemiplegia.

There are several variations of hemiplegia. They are classified as:

  • Partial – retaining some control of the muscles
  • Complete – inability to move any muscle
  • Permanent – muscle control does not come back
  • Temporary – some muscle control returns
  • Flaccid – muscles become flabby and may shrink
  • Spastic – muscles become stiff and may spasm


Muscle movement is controlled by signals sent to the body by the brain and spinal cord. When brain or spine damage occurs, the signals are not able to direct the muscles to move, resulting in paralysis. Most cases of hemiplegia occur as a result of a stroke.

Other causes of hemiplegia include the following:


Evaluation of hemiplegia involves the following imaging tests and diagnostic procedures:

  • X-ray
  • CT scan
  • MRI
  • Myelography
  • Electromyography (EMG)
  • Complete blood count


Secondary conditions of hemiplegia are problems that you might experience as a result of the weakness. Sometimes, these problems are not noticeable right away and may develop months after you first notice hemiplegia.

Some of the complications of hemiplegia include:

  • Bladder problems- incontinence and/or urinary retention
  • Bowel control problems
  • Pain
  • Deep vein thrombosis (DVT)
  • Autonomic dysreflexia
  • Depression
  • Respiratory difficulties
  • Heart disease
  • Sepsis
  • Pressure wounds
  • Muscle spasticity
  • Muscle atrophy


Sometimes, muscle strength may improve on its own. Hemiplegia may respond to treatment. Some treatments for hemiplegia include:

  • Physical therapy: Exercise is helpful to keep joints loose and flexible. Carefully designed therapy techniques prevent muscle atrophy and spasticity. Physical therapy also helps prevent the complications of hemiplegia and hemiparesis - such as heart disease, diabetes, pressure sores, obstructive pulmonary disease, urinary tract infections.
  • Occupational therapy: This is a type of therapy that is focused on learning how to take care of practical tasks and everyday activities, such as self-care.
  • Mobility aids: Mobility aids include manual and electric wheelchairs and scooters as well as braces, canes, and walkers. These aids can help you lead an independent, active life even if you have hemiparesis or hemiplegia.
  • Assistive technology: Use of voice-activated devices, computers, telephones and lighting systems is becoming more available and practical to use.
  • Adaptive equipment: Use of specially designed devices for driving, eating utensils, health and beauty aids can help in practical day to day activities.

A Word From Verywell

Hemiplegia and hemiparesis are difficult conditions to adjust to, but there are steps you can take to make living with hemiplegia or hemiparesis easier. Neurological illnesses that cause hemiplegia and hemiparesis are not uncommon, and there are resources that can help you through your recovery as well as resources that can provide assistance in helping you with practical aspects of life.

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