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Muscle weakness happens when your full effort doesn’t produce a normal muscle contraction or movement. It’s sometimes called reduced muscle strength, muscular weakness, or weak muscles.
Whether you’re ill or simply need rest, short-term muscle weakness happens to nearly everyone at some point. A tough workout, for instance, will exhaust your muscles until you’ve given them a chance to recover with rest.
But if you develop persistent muscle weakness, or muscle weakness with no apparent cause or normal explanation, it may be a sign of an underlying health problem. Voluntary muscle contractions are usually generated when your brain sends a signal through your spinal cord and nerves to a muscle. If your brain, nervous system, muscles, or the connections between them are injured or affected by disease, your muscles may not contract normally. This can produce muscle weakness.
Many health conditions can cause muscle weakness. Examples include:
If you experience muscle weakness for which there’s no normal explanation, make an appointment with your doctor. You’ll be asked about your muscle weakness, including how long you’ve had it and which muscles have been affected. Your doctor will also ask about other symptoms and your family medical history.
Your doctor may also check your reflexes, sensation, and muscle tone. If needed, they may order one or more tests, such as:
Once they’ve determined the cause of your muscle weakness, your doctor will recommend appropriate treatment. Your plan will depend on the underlying cause of your muscle weakness, as well as the severity of your symptoms. In some cases, physical therapy may be helpful. Your doctor may also recommend medication, surgery, or other treatments.
In some cases, muscle weakness can be a sign of something very serious, such as a stroke. If you experience any of the following symptoms, call 911 immediately:
Written by: JC Jones MA, RN
Medically reviewed on: Nov 30, 2016: William Morrison, MD
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