Hemiparesis is a slight weakness — such as mild loss of strength — in a leg, arm, or face. It can also be paralysis on one side of the body.

Hemiplegia is a severe or complete loss of strength or paralysis on one side of the body.

Symptoms can range from a minor weakness to a severe weakness or paralysis on one side of the body, resulting in:

  • difficulty standing
  • difficulty walking
  • unusual sensations in the affected side of the body
  • strain on the unaffected side of the body caused by overcompensation

Symptoms of hemiplegia are more severe than hemiparesis. They involve a complete loss of strength or paralysis on one side of the body.

Although the paralysis may not be extensive, it could affect your ability to:

Your brain and spinal cord control muscle movement. If either your brain or spinal cord is damaged, they’re not able to direct the muscles. The result is paralysis.

Most cases of hemiparesis and hemiplegia are caused by stroke. Other causes include:

Your spinal cord and brain have a left side and a right side. The halves are identical. Each half controls the movements on one side of the body.

An injury to one side of the spinal cord or brain can result in weakness or paralysis on one side of the body (hemiparesis or hemiplegia).

To diagnose hemiparesis and hemiplegia, a doctor will most likely use a number of diagnostic procedures and imaging tests.

These might include:

The weakness or paralysis can result in both short- and long-term health complications, such as:

Treatments for either hemiparesis and hemiplegia will first address the cause.

To treat the weakness or paralysis, doctors will often recommend:

  • Physical therapy (PT). In this targeted training, a physical therapist can prevent muscle spasticity and atrophy while keeping joints flexible and loose.
  • Occupational therapy (OT). OT can help compensate for the lack of use of one side of the body. You may learn methods and techniques for taking care of common and practical activities.
  • Mobility aids. Aids such as wheelchairs and walkers can help in leading an independent life.
  • Adaptive equipment. Practical day-to-day tasks can be made easier with devices to facilitate driving, cleaning, eating, and more.
  • Assistive technology. Voice-activated devices such as telephones and computers can help with home and work productivity.
  • Alternative treatments. Other treatments may include dietary changes or acupuncture.

Hemiparesis is a mild or partial weakness or loss of strength on one side of the body. Hemiplegia is a severe or complete loss of strength or paralysis on one side of the body.

The difference between the two conditions primarily lies in severity. They can both be:

  • the result of the same causes
  • diagnosed the same way
  • treated similarly

Primarily caused by stroke, hemiparesis and hemiplegia can be caused by injuries or diseases that impact the brain and spinal cord.

Following diagnosis, your doctor can put together a treatment plan which may include physical and occupational therapies.