What should you know about McMahon rhabdomyolysis?

It can develop after unaccustomed strenuous exercise, crush injury, prolonged immobility, heat exposure or some medical conditions and medicines. Muscle pain, weakness, swelling and unusually dark urine may occur, but symptoms vary. Ordinary [Muscle Soreness After Exercise](/symptoms/muscle-soreness-after-exercise/) usually settles with recovery; severe or disproportionate symptoms need a different level of attention. Diagnosis commonly involves an examination and blood and urine tests.

Stop strenuous exercise and seek medical advice promptly if rhabdomyolysis is possible. Do not try to train through marked pain, weakness or swelling. A clinician can guide fluid intake and decide whether monitoring or hospital treatment is needed; avoid self-treating with medicines that may not suit your kidney function. Keep track of urine colour, urine amount, muscle symptoms and any trigger such as intense exercise or heat.

Seek urgent medical care for dark tea-coloured urine, much less urine than usual, severe muscle swelling, worsening weakness, faintness, confusion, vomiting or trouble breathing. Prompt assessment is also appropriate when severe muscle pain follows strenuous activity, especially with heat exposure or prolonged exertion. Rhabdomyolysis can cause problems before a person feels severely unwell.

Do my symptoms require blood or urine testing? What activity, medicines or supplements should I pause? How should I drink fluids? When can I safely resume exercise, and which warning signs should bring me back?