Muscle Weakness: Causes & Treatment

 

Fatigue and muscle injuries are just many conditions that can cause muscle weakness. However, it can also be a sign of other conditions or a serious problem with the nervous system. You can find out why you have it and what to do about it by speaking with a healthcare professional.

Even something as simple as a tough workout can result in short-term muscle weakness, which is common. On the other hand, chronic muscle weakness without a known reason might be a sign of an underlying medical condition.

When maximal effort fails to result in a typical muscle contraction or movement, muscle weakness occurs.

It is occasionally referred to as:

• Diminished muscular strength

• Weak muscles

•  Muscular weakness

Typically, your brain communicates with a muscle via the spinal cord and nerves to cause voluntary muscle contractions.

Your muscles may not contract normally if the disease affects or damages your brain, nervous system, muscles, or the connections between them. Muscle weakness may result from this.

Also Read: Rheumatoid Arthritis, Symptoms, Causes, Diagnosis and Treatment

What is Muscle weakness?

When muscles aren't as strong as they should be, it's called muscle weakness. There are numerous causes for it, most of which are normal and temporary. However, a medical condition may also be indicated by muscle weakness.

Depending on the cause, muscle weakness can feel different. You may encounter:

• Loss of strength

• Having trouble completing routine tasks or activities

• Pain when using the muscles that are impacted

• Stability or balance issues when standing or walking

• Shaking or trembling

Potential causes muscles weakness:

Muscle weakness can result from a variety of medical conditions.

Among the examples are:

• Multiple sclerosis (MS)

• Amyotrophic lateral sclerosis (ALS)

•  Muscular dystrophies

•  Neuromuscular disorders

•  Autoimmune diseases, including Graves' disease, myasthenia gravis, and Guillain-Barré syndrome;

The following conditions can also cause muscle weakness:

•  Herniated disc

•  Stroke

•  Syndrome of chronic fatigue (CFS)

•  Neuralgia, a form of nerve damage, peripheral neuropathy, a sharp burning or pain that follows the path of one or more nerves.

• Hypotonia, a lack of muscle tone that is typically present at birth

•  Long-term bed rest or immobilization due to polymyositis, or chronic muscle inflammation

•  Alcoholic myopathy can result from alcoholism

Complications from specific viruses and infections can also result in muscle weakness, such as:

• West Nile virus-induced 

• polio

• Rheumatic fever

Muscle weakness is another symptom of botulism, a rare and dangerous disease brought on by the Clostridium botulinum bacteria.

Muscle weakness is another side effect of long-term use of some drugs.

Among these medications are:

• Statins and other lipid-lowering medications

• Antiarrhythmic medications

• Procainamide corticosteroids, amiodarone (Pacerone)

• Colchicine (Colcrys, Mitigare), which is used to treat gout

Diagnosis of the root cause of weakened muscles:

Make an appointment with your healthcare provider if you have muscle weakness that has no known cause.

Our Healthline FindCare tool allows you to schedule an appointment with a primary care physician in your area.

You will be questioned regarding the weak muscles, including the duration of the weakness and the specific muscles that are impacted. Inquiries about your family medical history and other symptoms will also be made by your healthcare provider.

Additionally, your doctor might examine your:

• Reflexes

•  Senses

•  Muscle tone

If necessary, they might request one or more tests, like:

• CT scan

•  MRI scans to look at your body's internal structures; nerve tests to evaluate the function of your nerves

• Using electromyography (EMG) to measure muscle nerve activity

•  Blood tests to look for indications of infection or other disorders

Treatment:

Options for treating muscle weakness:

Your healthcare provider will suggest the best course of action after identifying the reason behind your muscle weakness. The underlying cause of your muscle weakness and the intensity of your symptoms will determine your course of treatment.


The following are a few possible treatments for ailments that result in muscle weakness:

Physical therapy

Physical therapists can recommend exercises to help people with conditions like ALS or MS live better lives.

For instance, to help someone with MS strengthen muscles that have weakened due to inactivity, a physical therapist might recommend progressive resistance training.

To avoid muscle stiffness, a physical therapist may suggest range-of-motion exercises and stretching for an individual with ALS.

Occupational therapy

Occupational therapists can recommend upper-body strengthening exercises. They can also suggest tools and assistive technology to help with daily tasks.

Occupational therapy can be particularly beneficial when recovering from a stroke. Therapists may recommend exercises to improve motor skills and address weakness in one side of the body.

Medication Ibuprofen and acetaminophen are examples of over-the-counter (OTC) pain relievers that can help manage pain related to conditions like:

• Peripheral neuropathy

• CFS

• Neuralgia

Changes in diet

Electrolyte imbalances can be corrected by altering your diet. Depending on your needs, your doctor might also advise taking supplements like potassium oxide, magnesium oxide, or calcium.

Surgery

 Herniated discs and hyperthyroidism are certain conditions that may be treated with surgery.

Is it possible to prevent muscle weakness?

While many causes of muscle weakness cannot be avoided, some can. You can lower your chance of developing muscle weakness by doing the following:

• Get in shape. Your physical strength can be increased through strength training. Later muscle weakness might be prevented or reversed with that.

• Recognize your boundaries. Avoid overstretching your muscles to the point of damage.

• Keep your nervous system safe. When engaging in work or leisure activities, wear protective gear such as padding or helmets. By doing this, injuries to the brain, spine, and nerves can be avoided. Additionally, injuries from collisions involving moving vehicles can be avoided by wearing seat belts.

• Control long-term illnesses. By doing this, certain illnesses may not worsen and result in muscle weakness. Taking medicine for epilepsy to stop seizures is one example of this.

Reference:

• Muscleweakness (hypotonia) in children. (n.d.) http://www.childrenshospital.org/conditions-and-treatments/conditions/m/muscle-weakness-hypotonia

• Latronico N, Gosselink R. A guided approach to diagnose severe muscle weakness in the intensive care unit (https://pmc.ncbi.nlm.nih.gov/articles/PMC4592111/). Rev Bras Ter Intensiva. 2015;27(3):199-201.

• NINDS hypotonia informationpage. (2019). https://www.ninds.nih.gov/Disorders/All-Disorders/Hypotonia-Information-Page

• Magee DJ, Manske RC. Principles and Concepts. In: Magee DJ, Manske RC, eds. Orthopedic Physical Assessment, 7th ed. Elsevier Inc. 2021:1-72.

• Weakness. (n.d.). https://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms/Weakness

• Naqvi U, Sherman AL. Muscle Strength Grading (https://www.ncbi.nlm.nih.gov/books/NBK436008/). 2023 Aug 28. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan.

• Newman G. How to Assess Muscle Strength (https://www.merckmanuals.com/professional/neurologic-disorders/neurologic-examination/how-to-assess-muscle-strength). Merck Manual (Professional Version). Last reviewed 8/2023.