The potentially life-threatening condition in which muscle tissue breaks down and releases its contents into the bloodstream is rhabdomyolysis.
Often shortened to “rhabdo,” the condition involves rapid destruction of damaged skeletal muscle. Causes include crush injuries, extreme exertion, heat illness, certain medications, drug use, infections, and inherited muscle disorders. Damaged cells release substances including myoglobin, creatine kinase, potassium, and phosphate into the blood.
Myoglobin can overload and injure the kidneys, while electrolyte disturbances may trigger dangerous heart-rhythm problems. Muscle pain, weakness, swelling, and dark tea-colored urine are possible signs, although symptoms vary and the classic urine color is not always present. Diagnosis commonly involves a blood test measuring creatine kinase.
Compartment syndrome is a possible complication of rhabdomyolysis, not the same condition. Muscular dystrophy is a group of inherited disorders, and myasthenia gravis is an autoimmune disorder affecting nerve-muscle communication; neither describes sudden muscle breakdown and bloodstream release.