7 Causes of Muscle Atrophy

Muscle atrophy, or loss of muscle mass, is often referred to as muscle wasting. It occurs when the body begins to degrade muscle tissue and has no way to rebuild it. A muscle that has wasted will be smaller than one that has not. For example, someone with a broken leg may experience a wasted quadriceps on that leg. The affected leg would appear smaller, such as narrower or thinner but not shorter, than the unaffected quadriceps on the other leg. Muscle wasting can occur in just one area or may be widespread throughout the entire body depending on the reasons for it. Wasted muscles lose strength and can reduce mobility, leading to a reduced quality of life for the sufferer.

There are basically two main types of muscle atrophy. These are disuse atrophy and neurogenic atrophy. While the symptoms are very similar for both of these types of atrophy, the causes are very different. Muscle wasting due to neurogenic atrophy is much less common but much more difficult to treat. That is why it can be very important for someone with muscle wasting to speak with a professional regarding the reasons for their atrophy. Physical therapy or other treatments can be beneficial in many cases but are often truly dependent on the causes of the original issue.

1. Lack of Physical Activity

Perhaps the most common cause of wasting of the muscles is due to lack of activity. This falls under disuse atrophy. When the muscles are not used enough, they tend to shrink. The body can utilize stored protein in the form of muscle easier than fat tissue for energy when the muscles are not worked on a regular basis. Wasting typically does not occur when muscles are in use. This type of atrophy is commonly seen in those who are bedridden. It can also occur in those who sit for long periods of time, such as with a desk job. This can also occur simply from decreased activity levels or in those who do not engage in regular activity.

While wasting is never good, muscle atrophy from lack of physical activity can be corrected with proper nutrition and exercise. Depending on the severity of the muscle loss, it is best to start slow with stretching and lifting with minimal weight resistance. Trying to do too much too quickly can lead to injury or damage to muscles and connective tissues, which can make the situation even worse. A physician or a physical therapist can make recommendations on the proper activities for an individual to get started.

2. Aging

Loss of lean muscle mass occurs naturally during the aging process. Beginning by about the age of 30, most individuals can expect to lose muscle mass every year. While this loss of muscle occurs more quickly for those with more sedentary lifestyles, even those who engage in regular exercise can expect to see some muscle loss over time. The process will speed up some time between the ages of 65 and 75.

Symptoms include weakness of the muscles and a loss of stamina, or the ability to keep going. This can lead to inactivity, which in turn leads to more muscle loss. To break out of this cycle, an increase in activity is recommended. Strength training and resistance exercises are the best way to increase muscle mass. It’s also important to consume enough healthy calories and to get enough protein in the diet. A trainer or a physical therapist can make recommendations that are personalized to a person’s ability, activity level, and degree of atrophy that has already occurred.

3. Alcohol-Associated Myopathy

Those who drink alcoholic beverages on a regular basis are at risk for developing muscle wasting. Alcohol-associated myopathy can actually alter the structure of muscle tissue while decreasing muscle strength and increasing muscle weakness. Both sides of the body are generally affected equally. This condition can be seen anywhere in the body but more frequently occurs in the legs. While this condition typically occurs gradually over a period of time, frequent binges can increase the rate of muscle loss.

When atrophy of the heart muscle occurs, the muscle stretches and begins to sag, making the heart unable to properly pump blood throughout the body. To treat this condition, the individual must avoid all alcoholic beverages, get proper nutrition, and maintain a recommended exercise program.

4. Burns

Those who suffer major burns are known to experience wasting of muscles. This is because burns initiate a series of responses within the body that can trigger inflammation, stress response, and an inability to transfer protein to muscle. Muscles can begin to break down fairly rapidly. Additionally, if the burned area is immobilized, patients will have to worry about atrophy due to disuse of the muscle.

The effects of atrophy has been seen in severe burn patients even a year following the incident. Many burn patients experience an increased metabolism following the injury. This can lead to the body breaking down stored muscle tissue to use for the energy required as a part of the healing process. Once the patient is able, proper nutrition and exercise can restore muscle mass.

5. Injuries

Other injuries can lead to muscle wasting as well. Broken bones and other accidents may result in immobilization, which leads to atrophy from disuse. However, some injuries can lead to nerve damage and the associated neurogenic muscle atrophy. When the nerves that supply muscle are damaged or restricted through an injury, muscle tissue can degrade.

Depending on the cause of the injury, muscle wasting may be progressive and it may be irreversible. In these cases, seeking help from a qualified physician may be able to slow progression and help the individual to find ways to overcome the limitations that are often imposed by loss of muscle mass.

6. Malnutrition

One of the most recognizable symptoms of malnutrition is muscle wasting. The body requires protein and a host of other nutrients to properly break down foods into muscle tissue. If an individual is not consuming enough nutrients, the body will break down current muscle to keep the internal organs functioning properly.

There are certain diseases and medical conditions that can create malnutrition and lead to atrophy of the muscles, specifically cancer, heart problems, and diseases that affect digestion. The prognosis for increasing muscle mass depends on the initial cause. Working with a primary care provider or specialists may be necessary to regain muscle strength and mass.

7. Stroke

Because stroke can cause paralysis or weakness, especially on one side of the body, atrophy of muscles is commonly seen in these patients due to disuse. However, disuse is not the only way that having a stroke affects muscles. There is a complex series of events that are triggered by stroke, including inflammation and denervation, that can lead to wasting of muscle tissue.

Depending on the severity of the damage, patients may regain some muscle mass if they are able to regain movement in affected areas. Patients should work with their physician or physical therapist for the appropriate exercise recommendations.