Which condition involves the breakdown of muscle tissue?

Which condition involves the breakdown of muscle tissue?

• A. Fibromyalgia
• B. Muscular dystrophy
• C. Myasthenia gravis
• D. Rhabdomyolysis

Answer: (D)

Rhabdomyolysis is the process where skeletal muscle tissue breaks down, releasing its internal contents, including myoglobin and enzymes, into the bloodstream. This can happen after severe injury, crush injuries, extreme exertion, or exposure to certain drugs or toxins. The released myoglobin can damage the kidneys, leading to dark-colored urine and potential acute kidney injury, so recognizing it early and treating with aggressive IV fluids to protect kidney function is key. This sets it apart from other muscle conditions: fibromyalgia is a chronic pain syndrome without actual muscle breakdown; muscular dystrophy involves genetic weakness and progressive degeneration of muscle; myasthenia gravis is an autoimmune problem affecting neuromuscular transmission rather than muscle cell destruction. In practice, look for signs like severe muscle pain or swelling after injury or intense exercise, and tea-colored urine, with labs showing very high CK and possible electrolyte disturbances. Management centers on rapid, large-volume isotonic fluid administration, monitoring urine output and electrolytes, and treating complications as needed.

Rhabdomyolysis is the process where skeletal muscle tissue breaks down, releasing its internal contents, including myoglobin and enzymes, into the bloodstream. This can happen after severe injury, crush injuries, extreme exertion, or exposure to certain drugs or toxins. The released myoglobin can damage the kidneys, leading to dark-colored urine and potential acute kidney injury, so recognizing it early and treating with aggressive IV fluids to protect kidney function is key. This sets it apart from other muscle conditions: fibromyalgia is a chronic pain syndrome without actual muscle breakdown; muscular dystrophy involves genetic weakness and progressive degeneration of muscle; myasthenia gravis is an autoimmune problem affecting neuromuscular transmission rather than muscle cell destruction. In practice, look for signs like severe muscle pain or swelling after injury or intense exercise, and tea-colored urine, with labs showing very high CK and possible electrolyte disturbances. Management centers on rapid, large-volume isotonic fluid administration, monitoring urine output and electrolytes, and treating complications as needed.