Muscle Atrophy: Causes, Symptoms, Testing and Treatment
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer: What is muscle atrophy?
Muscle atrophy is muscle loss or thinning that reduces muscle size, mass and strength. It may happen because a person is not using the muscles enough, or because a nerve problem prevents the muscles from receiving the signals needed for normal contractions. [1]
A healthcare provider evaluates the pattern of muscle loss, symptoms and possible causes. Treatment depends on the type of atrophy and may include exercise, nutrition, physical therapy, electrical stimulation, ultrasound therapy or surgery for a contracture. [1]
What the research says
Electrical stimulation may modestly improve muscle mass in adults with muscle loss, but the evidence is low-certainty. A meta-analysis of 18 randomized trials (676 adults with sarcopenia or secondary muscle loss) found that neuromuscular electrical stimulation (NMES) improved muscle mass compared with control conditions (SMD 0.66, 95% CI 0.30–1.02), with substantial heterogeneity. Community-dwelling older adults showed the most consistent benefit, while hemodialysis patients showed no clear improvement (Jiang et al., Muscle Nerve, 2026). [2]
Electrical stimulation also helped children with nerve-related conditions move better. A systematic review and meta-analysis of 18 studies (595 children and adolescents aged 3 to 14 with chronic neurological disorders) found that NMES improved muscle strength, movement biomechanics and functional mobility in children with cerebral palsy, spinal muscular atrophy and obstetric brachial plexus injury. The pooled effect on gross motor function was SMD 0.41 (95% CI 0.19–0.64) (Cobo-Vicente et al., Phys Ther, 2021). [3]
What does muscle atrophy look like?
Muscle atrophy is the loss or thinning of muscle tissue. The affected muscles look smaller than normal, and muscle mass and strength decrease. Atrophy can affect one area or more than one area, depending on its cause. [1]
One arm or one leg may look smaller than the other. A person may also notice weakness, reduced movement, difficulty walking or balance problems. [1]
Muscle atrophy is different from muscle hypertrophy, which is an increase in muscle mass because muscle fibers become larger or thicker. [1]
What are the two main types of muscle atrophy?
Muscle atrophy has two main types, and the distinction matters because the cause influences testing, treatment and the likelihood of reversal.
Type | Description |
Disuse (physiologic) atrophy | Develops when muscles are not used enough. The body breaks muscle down, decreasing its size and strength. |
Neurogenic atrophy | Develops when an injury or disease affects the nerves that connect to muscles. Damaged nerves cannot trigger the contractions needed for muscle activity. |
The distinction matters because the cause influences testing, treatment and the likelihood of reversal. A healthcare provider must determine the type rather than relying on appearance alone.
What are the symptoms of muscle atrophy?
Symptoms differ depending on the cause. The most obvious sign is reduced muscle mass, but muscle atrophy may also affect strength, sensation, movement, speech, swallowing and memory. [1]
Symptom or sign | How it may appear |
Reduced muscle mass | A muscle or body part looks smaller than normal. |
Uneven size | One arm or leg is smaller than the other. |
Weakness | Weakness in one arm or leg, or weakness in the face or throat. |
Numbness or tingling | Tingling, numbness or altered sensation in the arms or legs. |
Movement and balance changes | Trouble walking or balancing. |
Speech or swallowing changes | Difficulty speaking or swallowing. |
Memory changes | Gradual memory loss. |
In the limbs, a person may feel tingling, numbness or weakness. If atrophy affects muscles in the face or throat, the facial muscles may feel weak and speaking or swallowing may become difficult. [1]
These symptoms do not identify the cause by themselves. New or progressive muscle loss, weakness, sensory changes or difficulty speaking or swallowing should be discussed with a healthcare provider. Sudden weakness or numbness of the face, arm or leg, especially on one side, or sudden trouble speaking can be a stroke: call 911.
What causes muscle atrophy?
The cause depends on the type. Disuse atrophy develops when muscles are not used enough. The body then breaks down muscle because it is not maintaining muscle tissue that is being used less. [1]
Causes and situations associated with disuse atrophy
Disuse atrophy may be associated with a sedentary lifestyle, malnutrition, insufficient exercise, a desk job, bed rest, a genetic muscle disorder such as muscular dystrophy, inability to move a limb after a stroke or with dermatomyositis, and age-related atrophy called sarcopenia. [1]
A lack of movement is not always a choice. Pain, illness, injury, hospitalization, neurological disease or limited mobility can all reduce how much a muscle is used. A provider can look for the underlying reason rather than assuming that inactivity is the whole explanation.
Causes and conditions associated with neurogenic atrophy
Neurogenic atrophy occurs when injury or disease affects the nerves connecting to muscles. When nerve signals cannot trigger normal muscle contractions, muscle activity decreases and the body may break down muscle tissue. [1]
Conditions that can affect these nerves include amyotrophic lateral sclerosis, Charcot-Marie-Tooth disease, Guillain-Barré syndrome, carpal tunnel syndrome, polio, spinal cord injury and multiple sclerosis.
How quickly can muscles atrophy?
Timing depends on age, fitness level and the cause of atrophy. When atrophy results from disuse, the process can start within two to three weeks of not using the muscles. Neurogenic atrophy may develop sooner, depending on the health condition. [1]
This timing is a general description, not a way to diagnose muscle loss. A healthcare provider can assess whether the change is consistent with disuse, nerve-related disease or another cause.
How is muscle atrophy diagnosed?
A healthcare provider asks about symptoms and performs a physical examination. They may look at the arms and legs and measure muscle mass. [1]
Possible tests include a blood test, muscle or nerve biopsy, electromyography, nerve-conduction studies, X-rays, CT scans and MRI scans. The tests selected depend on the symptoms and the suspected cause. [1]
Evaluation method | What it may help assess |
Physical exam | Muscle size, strength, movement and related findings. |
Blood test | General or cause-related health information. |
Muscle or nerve biopsy | Tissue or nerve changes when a biopsy is appropriate. |
Electromyography (EMG) | Electrical activity of muscles and related nerve function. |
Nerve-conduction studies | How signals travel through nerves. |
X-ray, CT or MRI scan | Structural findings involving relevant body areas. |
No single test in this list is appropriate for every person. The provider chooses testing based on the pattern of muscle loss and associated symptoms.
Can muscle atrophy be reversed?
Disuse atrophy can sometimes be reversed with exercise and a healthy diet. A healthcare provider may begin an exercise program that includes pool-based activity because working out in water can reduce the workload on muscles. [1]
Neurogenic atrophy typically cannot be reversed because of the physical damage to nerves. However, treatment may still aim to maintain muscle mass and strength and support function. [1]
Type | Reversal and recovery |
Disuse atrophy | Usually reversible, although improvement takes time and depends on severity. |
Neurogenic atrophy | Typically cannot be reversed because of nerve damage; supportive treatment may help maintain mass and strength. |
How is muscle atrophy treated?
Treatment depends on the type and cause. For disuse atrophy, a provider may recommend regular exercise, better nutrition, physical therapy or an individualized exercise plan. If certain joints cannot be actively moved, still exercises may be possible while wearing a splint or brace. [1]
A dietitian may help create a healthy eating plan, and a provider may suggest nutritional supplements. Supplements should be discussed with a healthcare professional rather than started automatically. [1]
For neurogenic atrophy, a physical therapist may use electrical stimulation. Electrodes placed over the muscles send small electrical impulses to the nerves and muscles, attempting to produce an artificial contraction. This may help some people maintain muscle mass and strength. [1]
A physical therapist may also recommend ultrasound therapy, which uses sound waves to promote muscle healing. If a contracture develops, surgery may be performed to correct it. A contracture occurs when muscle tissue becomes fibrous, making the muscle hard to stretch and limiting movement. [1]
How long does recovery take?
The time needed to regain muscle depends on the type of atrophy and how severe it was. Disuse atrophy is usually reversible, but recovery does not happen overnight.
Regular exercise and a healthy diet can help with recovery from disuse atrophy. Improvement may begin after a few months, but it can take much longer to regain full strength. [1]
For neurogenic atrophy, recovery expectations depend on the underlying nerve problem and the extent of nerve damage. Neurogenic atrophy typically cannot be reversed, though treatment may help maintain muscle mass and strength.
How is muscle atrophy different from muscle hypertrophy?
Muscle atrophy means a loss of muscle mass. Muscle hypertrophy means an increase in muscle mass because muscle fibers become larger or thicker. [1]
Strength training and high-intensity interval training are workout routines that may produce hypertrophy. A person with muscle loss or weakness should ask a qualified provider what type and intensity of activity are appropriate. [1]
Term | Meaning |
Muscle atrophy | Loss or thinning of muscle tissue. |
Muscle hypertrophy | Increase in muscle mass as muscle fibers become larger or thicker. |
When should you see a healthcare provider?
Reach out to a healthcare provider if a part of your body looks smaller or feels weaker. Diagnosing muscle atrophy is not always easy, but evaluation can help identify a suitable plan. [1]
Bring information about when the change started, whether it affects one side or several areas, any numbness or tingling, changes in walking or balance, and any difficulty speaking or swallowing. These details can help the provider decide what to examine and whether testing is needed.
How can people live with muscle atrophy?
Rebuilding muscle can be difficult and may require patience. A healthcare provider can recommend a plan for exercise, nutrition, physical therapy or other treatment based on the cause.
Following the plan consistently may help rebuild muscle mass and strength when recovery is possible. If the plan is difficult to follow, discuss barriers with the care team so it can be adjusted safely.
Discussion point | Why it can help |
Type of atrophy | Sets realistic expectations for reversal and maintenance. |
Suspected cause | Guides testing and treatment choices. |
Safe movement | Helps match exercise or therapy to current ability. |
Nutrition | Identifies whether dietary support or a dietitian may be useful. |
Strength goals | Gives follow-up visits a clear way to track progress. |
Conclusion: muscle loss deserves a clear evaluation plan
Muscle atrophy is the loss or thinning of muscle tissue, and it can have many causes. Disuse atrophy happens when muscles are not used enough, while neurogenic atrophy results from nerve injury or disease. Symptoms may include visible muscle loss, weakness, numbness, tingling, balance problems and difficulty speaking or swallowing.
A healthcare provider can examine the affected muscles, investigate possible causes and choose appropriate tests. Disuse atrophy can sometimes be reversed with exercise and nutrition, while neurogenic atrophy typically cannot be reversed because of nerve damage. For more clear, compassionate health explainers, explore Rinnit.com's health library and bring new or progressive weakness to a qualified healthcare professional.
Frequently Asked Questions
What is muscle atrophy?
Muscle atrophy is the loss or thinning of muscle tissue. It makes muscles look smaller and can decrease muscle mass and strength.
What are the first signs of muscle atrophy?
The most obvious sign is reduced muscle mass. Other possible signs include one arm or leg being smaller than the other, weakness, numbness, tingling, trouble walking or balancing, difficulty speaking or swallowing, facial weakness and gradual memory loss.
What causes muscle atrophy?
Causes include not using muscles enough, malnutrition, age, genetics and certain medical conditions. Nerve injury or disease can cause neurogenic atrophy.
What is disuse atrophy?
Disuse, or physiologic, atrophy happens when muscles are not used enough. The body breaks down muscle tissue, reducing muscle size and strength.
What is neurogenic atrophy?
Neurogenic atrophy happens when an injury or disease affects the nerves that connect to muscles. The damaged nerves cannot trigger the contractions needed for normal muscle activity.
How soon can muscle atrophy begin?
When atrophy is caused by disuse, the process can start within two to three weeks of not using the muscles. Neurogenic atrophy may develop sooner depending on the health condition.
Can muscle atrophy be reversed?
Disuse atrophy can sometimes be reversed with exercise and a healthy diet. Neurogenic atrophy typically cannot be reversed because of nerve damage, although treatment may help maintain muscle mass and strength.
What tests are used for muscle atrophy?
A provider may use a physical exam, blood test, muscle or nerve biopsy, EMG, nerve-conduction studies, X-rays, CT scan or MRI scan. The selected tests depend on the symptoms and suspected cause.
Can nutrition help muscle atrophy?
For disuse atrophy, better nutrition may be part of treatment. A provider may involve a dietitian and may suggest nutritional supplements.
Can physical therapy help?
A provider may recommend physical therapy or an exercise plan. For neurogenic atrophy, electrical stimulation may help some people maintain muscle mass and strength.
What is a contracture?
A contracture occurs when muscle tissue becomes fibrous, making it difficult to stretch the muscle and limiting movement. Surgery may be used to correct a contracture.
How long does it take to recover muscle?
Recovery depends on the type and severity of atrophy. Disuse atrophy is usually reversible, but improvement may take months and full strength may take much longer.
When should I contact a provider?
Contact a healthcare provider if part of your body looks smaller or feels weaker. An evaluation can help clarify the cause and guide a treatment plan.
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References
Cleveland Clinic. Muscle Atrophy: Causes, Symptoms & Treatment. Cleveland Clinic. Updated January 21, 2022. https://my.clevelandclinic.org/health/diseases/22310-muscle-atrophy
Jiang Y, Gao Y, Wang R, et al. Efficacy of Neuromuscular Electrical Stimulation in Mitigating Muscle Mass Loss: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Muscle Nerve. 2026;74(5):1387-1397. PMID 42698133. https://doi.org/10.1002/mus.70396
Cobo-Vicente F, San Juan AF, Larumbe-Zabala E, et al. Neuromuscular Electrical Stimulation Improves Muscle Strength, Biomechanics of Movement, and Functional Mobility in Children With Chronic Neurological Disorders: A Systematic Review and Meta-Analysis. Phys Ther. 2021;101(10):pzab170. PMID 34184031. https://doi.org/10.1093/ptj/pzab170
Disclaimer
This article is for general educational purposes and is not a substitute for professional medical advice, diagnosis or treatment. Always seek the advice of a qualified healthcare professional with any questions about a medical condition or treatment.
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