What is Muscle Atrophy: A Complete Guide

Atrophy is a kind of condition in which the size of muscles, tissues, or body part become reduced. As a result, the atrophied muscles or body part appears small. When atrophy occurs in the muscles, it is called muscle atrophy1. There are maybe physiological and genetic reasons for the occurrence of atrophied muscles.

This loss of muscle tissues due to muscle atrophy is not good for health and physical appearance. It increases the chances of injuries and also affects the person’s life as well. Hence, it is very essential to be aware of such kind of health condition before it makes your life worse.

If you are also nescient about muscle atrophy, and want to know what is muscle atrophy then this article going to be helpful for you. It is a complete guide on what is muscle atrophy so don’t skip it in the middle and read till the end.

you will be getting advantageous information from this article on What is Muscle Atrophy. Let’s dive into this complete guide on what is muscle atrophy.

What is Muscle Atrophy: A Complete Guide

Muscle atrophy is the condition in which muscle mass gets reduced. This can happen due to various reasons including muscle injury, lack of physical activity, or malnutrition. In this condition, reduced muscle activity leads to muscle wasting.

The lack of physical activity for long period gives rise to muscle inactivity. As a result, person isn’t able to do muscular movements, faces difficulty in muscle coordination, and losses muscle strength.

To know more on what is muscle atrophy just scroll down more and read it.

Muscle Atrophy Causes

To understand what muscle atrophy is, it is essential to know its causes. Knowledge of its cause will help you reduce the risk of muscle atrophy. There are many reasons for muscle atrophy but the most common reasons are as.

1. Neurological Issues

Neurological issues2 are associated with neurogenic muscle atrophy. When the nerves of a muscle get damaged due to an injury or damage. As a result, the transfer of signals from nerves to the brain does not happen.

Without signaling pathways, muscles do not contract. And the loss of muscle contraction will result in the loss of muscle activity.

When muscles don’t get signals, then the contractile proteins are also not going to function properly. This is the major cause of muscle atrophy.

Although neurogenic muscle atrophy is severe, you can cure it through physical therapy.

2. Medical Conditions

There are some medical conditions are also contribute to the cause of muscle atrophy or muscle wasting.

#1 Muscular dystrophy

It is a progressive muscle weakening disorder that passes from one generation to other. As it is a genetic disorder.

Muscular dystrophy occurs due to the genetic mutation in the genes of a particular muscle group. The mutation in gene takes place at any period of life, it is not restricted to the age of a person.

As it is a rare disorder hence it is too difficult to find actual numbers of people affected with it. But the Centers for Disease Control and Prevention is still working on it to find how many people in the United States are suffering from muscular dystrophy.

#2 Osteoarthritis

Muscle wasting causes muscle pain, movement disability, or loss of muscle control. When the muscular tissue of joints gets affected and starts to not function properly it leads to the occurrence of skeletal muscle atrophy.

Osteoarthritis is a joint inflammatory disorder that is also associated with skeletal muscle atrophy. It happens when the inflammation occurs in the synovial fluid 3or ligaments of joints.

#3 Rheumatoid arthritis

Rheumatoid arthritis is a type of arthritis, an inflammatory disease related to joints. It is one of the chronic inflammatory diseases that causes muscle weakness.

It has been reported that most patients with RA show muscle weakening or loss of muscle mass issues. Hence it is clear that the risk of muscle atrophy is very high in rheumatoid arthritis4 patients.

As it is related to joints therefore the joint movements are affected in this case. From research, it has been found that almost 50-70% of muscular strength is lost during RA.

#4 Spinal muscular atrophy

It is a genetic disorder related to the central nervous system, peripheral nervous system, and voluntary muscles. That arises due to the deficiency of motor neuron protein. This one is the most common type of SMA, known as Chromosome 5 SMA5. Other kinds of spinal muscular atrophy are occurred due to gene mutation.

When any injury or damage happens to the spinal cord, the chances of spinal muscular atrophy increase.

As most of the nerve cells lie in the spinal cord that controls all the motor nerve cells and voluntary muscle. Due to the damage to nerve cells, the muscles don’t get any signals, which ultimately leads to a loss of movement or functional properties.

Spinal muscular atrophy involves the loss of motor nerve cells that why it is also called motor neuron disease. Research showed that the production of SMN protein will be beneficial not only to reduce the risk of SMA but also for its treatment.

#5 Polymyositis

This is another medical condition that causes muscle atrophy. It is not limited to a particular muscle part of the body. It affects the whole body’s muscles.

Polymyositis 6is considered to be an autoimmune disease. In which the body’s own immune system mistakenly attacks the muscle mass and breaks down the muscles which results in loss of muscle mass.

As the muscle mass of the whole body gets affected in polymyositis, hence the movement of both voluntary and involuntary muscles is affected. Even cardiovascular muscles are also inflamed and cause fluctuation in heart rhythms.

For a person with polymyositis, life becomes so difficult as they can’t able to do everyday activities. But this doesn’t mean they can’t get improvement. Through physical therapy, heat therapy, and immunosuppressive medicines the symptoms of polymyositis can be reduced.

The bitter truth is currently no cure is available for it only its symptoms can be treated through medical assistance.

#6 Multiple sclerosis

The muscle atrophy due to the damage of nerve cells of the brain and spinal cord is called multiple sclerosis. It arises with the development of the following symptoms including mobility loss, blurred vision, or in severe cases leads to paralysis.

Multiple sclerosis is considered to be a chronic disease as it directly affects the brain, which is the controlling site of every muscle movement.

Just like polymyositis, it is also an autoimmune disease in which the immune system attacks the central nervous system. The damage to the nerve fibers results in the loss of functional electrical stimulation as the flow of electrical impulses to the target cells from the brain does not take place.

#7 Dermatomyositis

Dermatomyositis is an inflammatory condition that is also responsible for muscle atrophy. Out of all medical conditions, this one mainly occurs more in females than males.

Just like most muscle diseases, this one is also an inflammatory disease. It arises due to the inflammation in the muscle tissue of the skin, neck, upper arms, shoulders, and thighs. Due to that inflammation, the muscles of these regions undergo progressive muscle weakening and result in loss of muscle tissues.

It also develops the rashes on face, chest, and back. Facial weakness is also a common symptom of the development of dermatomyositis.

Well, its causes are still unknown to the researchers but they estimated that it is an autoimmune disease. This means the immune system mistakenly attacks healthy muscle tissues and causes inflammation.

#8 Amyotrophic lateral sclerosis

When the loss of muscle tissues and muscle strength is happen due to the progressive nervous system disease, then it is a sign of amyotrophic lateral sclerosis. It is first diagnosed in a baseball player hence it is named after him, Lou Gehrig’s disease.

The cause of ALS is not clear yet just like the above-mentioned medical conditions. It affects the motor nerve cells of the brain and spinal cord, and as a result, a person’s ability to perform physical activity is get affected.

The muscle atrophy occurs due to this medical condition affects cognitive and behavioral functioning as well. But the senses and bladder control functions are not get affected in ALS.

This is because it affects the motor neurons due to nerve protein degradation. Various researches have been conducted to find its cause, and they all end up on the genetic and environmental factors as causing factors of ALS.

3. Age

Age is the risk factor for the development of muscle atrophy. With the increase in age, the muscle mass started to reduce due to the decrease in the production of muscle protein.

The continuous reduction in muscle protein causes muscle loss or muscle wasting. In medical terms, this condition is called Sarcopenia.

Muscle weakness due to aging is an inevitable event. But it can be cured by improving lifestyle and taking medical assistance.

Muscle weakening in elder people
Image by toa55 on Unlimphotos

Sarcopenia is an age-related loss of muscle tissues, muscle fibers, or muscle cells, that leads to a decrease in skeletal muscle mass and strength. Hence, the main cause of this progressive muscle mass loss is the natural aging process.

It is also found the risk of sarcopenia is high in obese people and in them, this condition is termed sarcopenia obesity. The rate of occurrence of sarcopenia in people of age 60 and above is 5-13%. As the age increases the rate of development of sarcopenia increases for example, for people age 80 and above it is 11-50%.

4. Nutritional Deficiency

A healthy diet means taking all the nutrients which are essential for the body to perform all its functions. When there is any deficiency of proteins, carbohydrates, vitamins, and minerals in the body takes place it results in malnutrition.

The nutritional deficiency is also responsible for muscle atrophy or muscle wasting. This happens because of poor nutrition which is the reason for the cause of various health-related disorders. And this ultimately results in loss of muscle mass or muscle weakness.

There are many metabolic conditions that affect the nutrient-absorbing ability of the body. These are irritable bowel syndrome, cachexia, cancer, or celiac disease. All metabolic diseases are linked with weight loss and muscle mass loss. And any kind of reduction in muscle tissues and muscle fibers is a sign of muscle atrophy.

Hence it is very important to take a nutrient-rich diet to reduce the risk of muscle atrophy.

5. Genetics

There are various researches that showed the cause of muscle atrophy is genetic as well. That means it is also a kind of genetic disorder. Well, not all types of muscle atrophy occur due to gene mutation.

Some types of muscle atrophy are an example of a genetic disorders. The most common one is spinal muscle atrophy, which arises due to the mutation in SMN1 genes on chromosome 4. It is usually reported in children, but it can also occur at any age.

The cause of reduced muscle mass is genetic which means the gene gets inherited from one generation to another. If muscle atrophy is observed in any member of a family then the chances of its development in the next generation are very high.

Mutation in the genes that code for muscle protein results in the reduction of protein. That leads to muscle weakness and muscle atrophy.

Through this information about the causes of muscle atrophy, you will understand what is muscle atrophy. But this is not sufficient knowledge regarding what is muscle atrophy.

So check out the major types of muscle atrophy.

Muscle Atrophy Types

Muscle atrophy can be of three types based on its causes. these three types of muscle atrophy or muscle wasting are physiologic, pathologic, and neurogenic muscle atrophy.

1. Physiologic Muscle Atrophy

Usually, this kind of muscle atrophy arises when the muscles are not used enough. It mostly occurs in those people who perform less physical activity, doing seated work, or at bed rest. As this happens due to less use of muscles hence, physical activities and muscle movement are the best way to treat physiologic muscle atrophy.

2. Pathologic Muscle Atrophy

Pathologic muscle atrophy occurs when the body gets some kind of illness or disease. There are some other medical conditions that are responsible for cause of pathologic atrophy. For example muscular inflammation, metabolic problems, or malnutrition.

Even corticosteroid therapies are also the reason for this kind of muscle atrophy. When a muscle becomes inactive for prolonged periods then the risk of muscle atrophy becomes high.

3. Neurogenic Muscle Atrophy

This is related to the central nervous system. As the nerves are get affected in this kind of muscle atrophy, therefore the most affected part in this atrophy is the central nervous system. This kind of muscle atrophy is more severe than others, as it can occur suddenly.

As nerve damage is the main reason for the development of neurogenic muscle atrophy. It can occur due to spinal cord injury, polio, or some other neural disorder.

Muscle Atrophy Symptoms

As muscle atrophy has different types according to its cause, similarly its symptoms are varies. Depending upon the type and cause of muscle atrophy, its symptoms would vary. The severity of muscle atrophy is also another factor in the development of various symptoms.

Generally, the following symptoms have been observed in a person who is suffering from muscle atrophy. These symptoms are;

  • Reduced muscle mass
  • Muscle weakness
  • Loss of muscle tissue
  • Muscle size decreases
  • Loss of muscle strength
  • Muscular pain
  • Atrophied muscles of the leg or arm appear short than normal
  • Difficulty in maintaining body balance
  • Facial weakness

In extreme cases of muscle atrophy, muscle loss ends up with memory loss. This condition arises only in the severe case of muscle atrophy.

Muscle Atrophy Diagnosis

Sometimes people ignore slight muscle pain or inflammation with concern that it might be the cause of muscle atrophy. So, it is always suggested to go for a medical check-up whenever you get the symptoms of muscle atrophy.

The knowledge about the diagnosis process will be beneficial to complete the infromation regarding what is muscle atrophy. The process of diagnosis will be easy when there is understanding on what is muscle atrophy.

The early diagnosis of muscle atrophy will be helpful not only in its treatment but also in recovering muscle loss. Diagnosis is also important to prevent muscle atrophy. There are various physical examinations or tests to diagnose muscle atrophy. Some of the common tests are as follows;

1. Blood Test

This is a very common test used for the diagnosis of every kind of disease. But in case of muscle atrophy, a blood test is done to detect the amount of creatine kinase proteins.

There are mainly three types of CK protein such as CK-MM in skeletal muscles, CK-MB in heart muscles, and CK-BB in brain tissues. The high amount of this protein is a sign of muscular injuries or muscular disorders including muscle atrophy.

2. Computed Tomography (CT)Scan

CT scan helps to detect the reduced muscle mass due to muscular dystrophy, muscle hypertrophy, or muscle disuse. Muscle atrophy results in a change in muscle mass or muscle tissue, that can be easily detected through CT imaging.

3. Nerve Conduction Studies

Nerve conduction studies are a process of diagnosis of muscle atrophy. It is usually done in case of neurogenic muscle atrophy to detect the dead nerves. In this test, the electrical stimulation is sent to the target nerves to check their ability to send these impulses to the muscle.

In this way, it can be easily detected whether the following nerve cells are working or not.

4. Muscle or Nerve Biopsy

The diagnosis of diseases related to muscle tissue or muscle contraction is done through muscle biopsy or nerve biopsy.

Muscle biopsy is conducted through a sample of muscle tissue that can be collected from the biceps (Upper arm muscles), thigh muscles, or shoulder muscles.

5. Electromyography

Electromyography is used to diagnose injuries or problems related to muscle tissue and nerve cells. Through this diagnosis, motor neuron signals are translated into graphs, sounds, and numerical values for the evaluation of the health of muscle cells and nerve cells.

Muscle Atrophy Treatment

After knowing what is muscle atrophy the next question will be how to treat muscle atrophy. So it is going to be important to add information regarding the treatment of muscle atrophy so that the improvement in muscle mass or physical activity takes place.

The knowledge of what is muscle atrophy will be incomplete without knowing its treatment or cure. So read this to get to know about its treatment.

1. Physical Therapy

The first thing that comes to treat muscle atrophy or muscle wasting is physical therapy. It is going to be helpful reduces the symptoms of muscle atrophy as well as preventing further damage due to muscle atrophy.

In physical therapy, various exercises and stretches are performed to improve muscle contraction and moveability. It also helps in improving muscle strength, muscle weakness, as well as muscle mass.

2. Ultrasound Therapy

This is a rarely used technique for the treatment of muscle atrophy. In this therapy, the beams of ultrasound energy are used to give stimulations to the atrophied muscles. Due to the given stimulations, the targeted muscle cells or tissues start contraction.

3. Functional Electrical Stimulation

Functional electrical stimulation is the best treatment to bring muscle contraction in atrophied muscles. In bed rest conditions this is the best way to stimulate movement in affected muscles.

In this technique, the electrical impulses are sent to the affected muscles.

4. Health Diet

Poor nutrition is the reason of development of muscle atrophy hence, a nutritional diet will be the way to deal with it. Taking proper nutrition will reduce the risk of muscle mass loss or muscle atrophy.

Some nutritional supplements are also helpful to recover muscle mass. These nutritional supplements are creatine and some amino acid supplementation. They play an effective role in the protein synthesis process and increase the amount of protein for muscle fibers. In this way, they help to improve reduced muscle mass.

5. Surgery

Surgery is usually considered in case of muscular deformity or severe damage to muscle fibers. When physical therapy and other treatment don’t work well then surgery will be done to bring back muscular moveability for muscle function and muscle contraction.

Final Note

Hope this article on ‘what is muscle atrophy’ will be helpful for you to understand not only what is muscle atrophy but also its diagnosis and treatment. Let us know in the comment which part of this article what is muscle atrophy you find the most informational.

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  4. Radu, Andrei-Flavius, and Simona Gabriela Bungau. “Management of rheumatoid arthritis: an overview.” Cells 10.11 (2021): 2857. ↩︎
  5. Jiang, Lingxia, et al. “Development and validation of a 4-color multiplexing spinal muscular atrophy (SMA) genotyping assay on a novel integrated digital PCR instrument.” Scientific Reports 10.1 (2020): 19892. ↩︎
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