Unexplained loss of muscle mass

What is unexplained loss of muscle mass?

Loss of muscle mass that occurs without an obvious cause like injury, illness, or immobilization is known as unexplained loss of muscle mass. This concerning condition has several potential causes:

• Age-related muscle loss (sarcopenia) - As we get older, we naturally lose muscle mass due to declining hormones and reduced physical activity. However, accelerated muscle loss in younger adults may indicate an underlying condition.


• Nutritional deficiencies - Lacking key nutrients like protein, vitamins D and B12, zinc, and iron can lead to muscle breakdown. Getting sufficient calories and macros is crucial for maintaining mass.


• Endocrine disorders - Diseases affecting hormones like testosterone, growth hormone, and thyroid hormone can result in decreased protein synthesis and muscle wasting over time.


• Medications - Certain drugs used to treat conditions like diabetes, gastroesophageal reflux, and depression have muscle loss as a side effect. Always review medications with doctors.


• Inflammatory diseases - Increased systemic inflammation due to illnesses like cancer, heart failure, or autoimmune disorders can activate protein degradation pathways in muscle.


• Neurological conditions - Disorders impacting nerve function may cause atrophy due to lack of stimulation. Examples include amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), and peripheral neuropathy.

Unintentional muscle loss symptoms

If you notice weakness doing daily tasks, fatigue, weight loss, smaller muscle size, or just feel physically weaker overall, see your doctor, especially if it occurs rapidly. They can run tests to uncover potential causes like vitamin deficiencies, hormonal imbalances, or other disorders leading to wasting.

Diagnosing what's behind muscle loss

Doctors may check blood counts, metabolic panels, thyroid, testosterone, or vitamin levels to pinpoint issues. Further testing like EMG/NCV studies, muscle/nerve biopsies, or imaging help assess nerve and muscle structure changes. Tracking diet, activity, and medications is also key.

Stopping and reversing muscle loss

The right treatment addresses the underlying trigger - hormone or vitamin replacement, adjusting medications, immune-modulating drugs, physical/occupational therapy. Regardless of cause, strength training and meeting protein needs (0.5-1g per pound bodyweight daily) helps regain and maintain mass. Some utilize supplements but consult a physician first.