Muscle function loss occurs when your muscles don’t work or move normally. Complete muscle function loss, or paralysis, involves being unable to contract your muscles normally.

If your muscles lose function, you won’t be able to properly operate the affected parts of your body. This symptom is often the sign of a serious problem in your body, such as a severe injury, drug overdose, or coma.

A loss of muscle function can be permanent or temporary. However, all instances of muscle function loss should be treated as a medical emergency.

The loss of muscle function can be either partial or total. Partial muscle function loss only affects a part of your body and is the main symptom of stroke.

Total muscle function loss, or paralysis, affects your entire body. It’s often seen in people with severe spinal cord injuries.

If a loss of muscle function affects both the top half and bottom half of your body, it’s called quadriplegia. If it affects only the bottom half of your body, it’s called paraplegia.

A loss of muscle function is often caused by a failure in the nerves that send signals from your brain to your muscles and cause them to move.

When you’re healthy, you have control over muscle function in your voluntary muscles. Voluntary muscles are skeletal muscles over which you have full control.

Involuntary muscles, such as your heart and intestinal smooth muscles, aren’t under your conscious control. However, they too can stop functioning. The loss of function in involuntary muscles can be fatal.

A loss of voluntary muscle function can be caused by a few things, including diseases affecting your muscles or nervous system.

Diseases of the muscles

Diseases that directly affect the way your muscles function are responsible for most cases of muscle function loss. Two of the more common muscle diseases that cause muscle function loss are muscular dystrophy and dermatomyositis.

Muscular dystrophy is a group of diseases that cause your muscles to become progressively weaker. Dermatomyositis is an inflammatory disease that causes muscle weakness, as well as a distinctive skin rash.

Diseases of the nervous system

Diseases that affect the way your nerves transmit signals to your muscles can also cause muscle function loss. Some nervous system conditions that cause paralysis are:

Many of the diseases that cause a loss of muscle function are hereditary and present at birth.

Injuries and other causes

Severe injuries also account for a large number of paralysis cases. For example, if you fall from a ladder and injure your spinal cord, you may experience a loss of muscle function.

Long-term drug use and medication side effects can also cause muscle function loss.

Before prescribing any treatment, your doctor will first diagnose the cause of your muscle function loss. They’ll start by reviewing your medical history.

The location of your muscle function loss, the parts of your body affected, and your other symptoms all give clues regarding the underlying cause. They may also conduct tests to assess your muscle or nerve function.

Medical history

Let your doctor know if your loss of muscle function came on suddenly or gradually.

Also, mention the following:

  • any additional symptoms
  • medications you’re taking
  • if you’re having trouble breathing
  • if your loss of muscle function is temporary or recurrent
  • if you have difficulty gripping items


After conducting a physical examination and reviewing your medical history, your doctor may administer tests to see if a nerve or muscle condition is causing your loss of muscle function.

These tests might include the following:

  • In a muscle biopsy, your doctor removes a small piece of your muscle tissue for examination.
  • In a nerve biopsy, your doctor removes a small piece of a potentially affected nerve for examination.
  • Your doctor can use an MRI scan of your brain to check for the presence of tumors or blood clots in your brain.
  • Your doctor can perform a nerve conduction study to test your nerve function by using electrical impulses.

Treatment options are tailored to your needs. They may include:

  • physical therapy
  • occupational therapy
  • medications such as aspirin or warfarin (Coumadin) to lower your risk of stroke
  • surgery to treat underlying muscle or nerve damage
  • functional electrical stimulation, which is a procedure used to stimulate paralyzed muscles by sending electrical shocks to your muscles

Some causes of muscle function loss are difficult to prevent. However, you can take steps to lower your risk of stroke and avoid accidental injury:

  • To lower your risk of stroke, eat a well-balanced diet that’s rich in fruits, vegetables, and whole grains. Limit salt, added sugar, solid fats, and refined grains in your diet.
  • Get regular exercise, including 150 minutes of moderate-intensity activity or 75 minutes of vigorous activity per week.
  • Avoid tobacco and limit your alcohol consumption.
  • To reduce your chance of accidental injury, avoid drinking and driving, and always wear your seatbelt while traveling in a motor vehicle.
  • Keep your home in good repair by fixing broken or uneven steps, tacking down carpets, and installing handrails beside stairs.
  • Clear ice and snow from your sidewalks, and pick up clutter to avoid tripping over it.
  • If you’re using a ladder, always position it on a level surface, fully open it before using it, and maintain three points of contact on the rungs while climbing. For example, you should have at least two feet and one hand or one foot and two hands on the rungs at all times.

In some cases, your symptoms will clear with treatment. In other cases, you may experience partial or complete paralysis, even after treatment.

Your long-term outlook depends on the cause and severity of your loss of muscle function. Talk to your doctor to learn more about your condition and outlook.