Muscle atrophy
Muscle wasting; Wasting; Atrophy of the muscles
Muscle atrophy is the wasting or loss of muscle tissue.
Causes
There are two types of muscle atrophy: disuse and neurogenic.
Disuse atrophy is caused by not using the muscles enough . This type of atrophy can often be reversed with exercise and better nutrition. People who are most affected are those who:
Not using the muscles enough
Hypotonia means decreased muscle tone.
- Have seated jobs, health problems that limit movement, or decreased activity levels.
- Are bedridden
- Cannot move their limbs because of stroke or other brain disease
Neurogenic atrophy is the most severe type of muscle atrophy. It can be from an injury to, or disease of, a nerve that connects to the muscle. This type of muscle atrophy tends to occur more suddenly than disuse atrophy.
Examples of diseases affecting the nerves that control muscles:
-
Amyotrophic lateral sclerosis
(ALS, or Lou Gehrig disease)
Amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis, or ALS, is a disease of the nerve cells in the brain, brain stem and spinal cord that control voluntary muscle movemen...
- Damage to a single nerve, such as carpal tunnel syndrome
-
Guillain-Barre syndrome
Guillain-Barre syndrome
Guillain-Barré syndrome is a serious health problem that occurs when the body's defense (immune) system mistakenly attacks part of the nervous system...
- Nerve damage caused by injury, diabetes, toxins, or alcohol
-
Polio (
poliomyelitis
)
Poliomyelitis
Polio is a viral disease that can affect nerves and can lead to partial or full paralysis. The medical name for polio is poliomyelitis.
- Spinal cord injury
Although people can adapt to muscle atrophy, even minor muscle atrophy causes some loss of movement or strength.
Other causes of muscle atrophy may include:
-
Burns
Burns
Burns commonly occur by direct or indirect contact with heat, electric current, radiation, or chemical agents. Burns can lead to cell death....
- Long-term corticosteroid therapy
-
Malnutrition
Malnutrition
Malnutrition is the condition that occurs when your body does not get enough nutrients.
-
Muscular dystrophy
and other diseases of the muscle
Muscular dystrophy
Muscular dystrophy is a group of inherited disorders that cause muscle weakness and loss of muscle tissue, which get worse over time.
-
Osteoarthritis
Osteoarthritis
Osteoarthritis (OA) is the most common joint disorder. It is due to aging and wear and tear on a joint.
-
Rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis (RA) is a long-term disease. It leads to inflammation of the joints and surrounding tissues. It can also affect other organs....
Home Care
An exercise program may help treat muscle atrophy. Exercises may include ones done in a swimming pool to reduce the muscle workload, and other types of rehabilitation. Your health care provider can tell you more about this.
People who cannot actively move one or more joints can do exercises using braces or splints .
Splints
A splint is a device used for holding a part of the body stable to decrease pain and prevent further injury.
When to Contact a Medical Professional
Call your provider for an appointment if you have unexplained or long-term muscle loss. You can often see this when you compare one hand, arm, or leg to the other.
What to Expect at Your Office Visit
The provider will perform a physical examination and ask about your medical history and symptoms, including:
Physical examination
During a physical examination, a health care provider studies your body to determine if you do or do not have a physical problem. A physical examinat...
- When did the muscle atrophy begin?
- Is it getting worse?
- What other symptoms do you have?
The provider will look at your arms and legs and measure muscle size. This may help determine which nerves are affected.
Tests that may be performed include:
- Blood tests
-
CT
scans
CT
A computed tomography (CT) scan is an imaging method that uses x-rays to create pictures of cross-sections of the body. Related tests include:Abdomin...
-
Electromyography
(EMG)
Electromyography
Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles.
-
MRI scans
MRI scans
A magnetic resonance imaging (MRI) scan is an imaging test that uses powerful magnets and radio waves to create pictures of the body. It does not us...
-
Muscle or nerve biopsy
Muscle or nerve biopsy
A muscle biopsy is the removal of a small piece of muscle tissue for examination.
-
Nerve conduction studies
Nerve conduction studies
Nerve conduction velocity (NCV) is a test to see how fast electrical signals move through a nerve.
- X-rays
Treatment may include physical therapy, ultrasound therapy and, in some cases, surgery to correct a contracture .
Contracture
A contracture develops when the normally stretchy (elastic) tissues are replaced by nonstretchy (inelastic) fiber-like tissue. This tissue makes it ...
References
Gibson J, Huntley J. The musculoskeletal system. In: Douglas G, Nicol F, Robertson C, eds. Macleod's Clinical Examination . 13th ed. Philadelphia, PA: Elsevier; 2013:chap 14.
Selcen D. Muscle diseases. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 421.
-
Active vs. inactive muscle - illustration
People may lose 20 to 40 percent of their muscle -- and, along with it, their strength -- as they age. Scientists have found that a major reason people lose muscle is because they stop doing everyday activities that use muscle power, not just because they grow older.
Active vs. inactive muscle
illustration
-
Muscular atrophy - illustration
Muscular atrophy is the decrease in size and wasting of muscle tissue. Muscles that lose their nerve supply can atrophy and simply waste away.
Muscular atrophy
illustration
-
Active vs. inactive muscle - illustration
People may lose 20 to 40 percent of their muscle -- and, along with it, their strength -- as they age. Scientists have found that a major reason people lose muscle is because they stop doing everyday activities that use muscle power, not just because they grow older.
Active vs. inactive muscle
illustration
-
Muscular atrophy - illustration
Muscular atrophy is the decrease in size and wasting of muscle tissue. Muscles that lose their nerve supply can atrophy and simply waste away.
Muscular atrophy
illustration
Review Date: 1/5/2016
Reviewed By: Joseph V. Campellone, MD, Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.