Acute kidney injury due to rhabdomyolysis

Warning features include severe muscle pain or swelling, unusual weakness, dark brown urine or much less urine than normal, particularly after extreme exertion, heat exposure, prolonged immobility, a crush injury, seizures, infection, or certain medicines and substances. Not everyone develops dark urine.

Damaged muscle cells release myoglobin, electrolytes and enzymes. Myoglobin can contribute to kidney damage, especially when dehydration or reduced kidney blood flow is also present. Electrolyte disturbances can affect the heartbeat and other organs, which is why this is more than ordinary post-exercise soreness.

Clinicians use the history, examination, blood tests, urine tests and urine output to assess muscle breakdown and kidney function. They may also check the heart rhythm and look for the trigger so it can be treated or removed.

Stop exercising, move away from heat and seek urgent medical care. Do not try to manage suspected rhabdomyolysis by forcing large amounts of fluid at home; fluid needs and electrolyte problems require clinical assessment, and some people cannot safely handle extra fluid. Bring a list of medicines, supplements and substances used, and explain recent exercise, heat exposure, illness, injury or immobilisation.

Hospital care may include carefully monitored intravenous fluids, repeated blood tests, urine measurement and treatment of the underlying cause. Severe kidney dysfunction or dangerous electrolyte imbalance can require specialist kidney care and temporary dialysis.

Go to an emergency department now for dark brown urine, sharply reduced urine, severe or rapidly worsening muscle pain or swelling, profound weakness, confusion, fainting, breathing difficulty, chest discomfort, palpitations, or persistent vomiting after a possible trigger. Call emergency services if the person is confused, collapses, has a seizure or cannot be transported safely.

Normal-looking urine does not exclude rhabdomyolysis. Intense symptoms that seem out of proportion to expected exercise soreness still warrant prompt evaluation.

Ask what likely triggered the muscle breakdown, how kidney function and electrolytes are changing, whether any medicine or supplement should be stopped, and what follow-up blood or urine testing is needed. Before resuming exercise, ask for specific guidance on activity progression, hydration, heat exposure and signs that should bring you back for care.