Loss of muscle, also known as muscle atrophy, occurs when muscle cells shrink or break down. This leads to reduced muscle mass, strength, and function. Common causes include lack of physical activity, illnesses, injuries, poor nutrition, and aging. Why does muscle loss happen? - Lack of exercise - Muscles need stimulation through activity to maintain their mass and strength. Without regular exercise, muscle cells shrink. - Illnesses & injuries - Certain diseases and injuries that limit movement can accelerate muscle loss. This includes stroke, arthritis, and being immobilized in a cast. - Poor nutrition - Not consuming enough protein and calories leads muscles to break down for energy. This commonly happens with eating disorders. - Aging - Starting around age 30, adults lose 3-5% of muscle mass per decade. This stems from reduced hormones and physical activity. What are the effects of muscle loss?