Muscle wasting, or atrophy, results from muscle disuse over a long period, or from malnutrition. The muscle tissue will decrease in bulk and length, which results in a noticeable loss of size and definition. Neurological deficiencies limit range of motion, and can also result in a loss of size and power, causing your muscles to atrophy. Muscle wasting can be debilitating, particularly if it results from malnutrition related to a disease.
Physical signs of malnutrition related muscle wasting include loss of appetite, dizziness upon standing up, low iron levels and other blood proteins, the "Merck Manual" notes. Deficiencies in protein and calories will cause the body to break muscle down to provide amino acids it needs to maintain organ function. Factors responsible for this condition include decreased food intake, or a disease causing a decrease in nutrient absorption or increased loss of nutrients, like cancer. Wasting occurs in stages, with changes becoming visible in laboratory testing values before any physical symptoms appear. Left untreated, muscle wasting can result in morbidity or death. Diseases such as irritable bowel syndrome, celiac sprue, protein-energy malnutrition, gluten allergy and cancer can cause nutrient-absorption issues and lead to muscle wasting, according to the "Merck Manual."
Physical activity pis crucial for your muscles to stay fit, appropriate in size, tone and capabilities. Signs of muscle wasting include visible weight loss, limited definition and loss of muscle strength. Sedentary jobs and lifestyles promote muscle atrophy because your daily routine doesn't include activity that challenges your muscles to grow or maintain their current size and strength level, according to the "New York Times" Health Guide. In addition to low physical activity, debilitating chronic diseases, such as cancer and severe burns, that keep sufferers bedridden can lead to muscle wasting, as can decreased physical activity related to aging.
Neurological causes of muscle wasting are severe and often happen rapidly. Some kind of damage to your nervous system limits physical abilities and range of motion and saps your strength. Symptoms of nerve damage and muscle wasting include uncontrolled twitching, muscle cramping, decreased strength and changes in your skin, hair and nails, the National Institute of Neurological Disorders and Stroke reports. Neurological diseases that can cause muscle wasting include myasthenia gravis, Guillain-Barré syndrome, Lou Gehrig's disease, muscular dystrophy and spinal-cord injuries, the "Merck Manual" adds.
- "New York Times" Health Guide: Muscle Atrophy
- National Institute of Neurological Disorders and Stroke: Peripheral Neuropathy Fact Sheet
- "The Merck Manual of Diagnosis and Therapy"; Mark Beers, M.D., and Robert Berkow, M.D.; 1999;