Background: Compartment syndrome is a well-recognised complication from trauma, burns, orthopaedic, vascular, or other surgery of the limbs. Hyponatremia related rhabdomyolysis leading to compartment syndrome of all four extremities with renal and hepatic impairment is rare.1,2,3 Although the rhabdomyolysis can occur without hyponatremia. Young men have the highest incidence of compartment syndrome, particularly after long-bone extremity fractures and strenuous exercise.4,5 We present a case of compartment syndrome of all four extremities following a brief episode of recreational jogging. Case: A 39-year-old Indian male, known hypertensive on nifidipine and indapamide was presented to the emergency department with generalized weakness, lower leg pain and cramps for 3 days. He had jogged for 2 km in warm temperatures. His symptoms worsened and he was unable to walk. Other complaints were headache, pain in both arms, and passing dark coloured urine for two days. Both his calf muscles were tender, tense to feel, and painful on flexion and extension. Dorsalis pedis pulses were weak but palpable bilaterally. Capillary refill was less than three seconds and sensation were intact in both lower limbs. Oxygen saturation of toes on both feet was 99%. Other body systems were unremarkable. His respiratory rate was 20 min− 1, blood pressure 210/110 mmHg, temperature 36.6°C, oxygen saturation (SpO2) 99%. Initial biochemistry results were serum creatinine 142 umol.l− 1, myoglobin 5791 ng.ml− 1, creatinine phosphokinase 19032 U.l− 1, sodium: 124 mmol.l− 1, aspartate aminotransferase (AST) 167 U.l− 1, and alanine aminotransferase (ALT) 49 U.l− 1 (Table 1). Doppler ultrasound of leg vessels showed no evidence of deep venous thrombosis, echogenicity of the muscles in the thigh and lower leg appeared within normal limits. Rhabdomyolysis was diagnosed and rehydration begun with Hartman's solution 1000 ml followed by 125 ml.h− 1. The patient was admitted to the ward for continued hydration and analgesia to treat the pain. His leg pain worsened overnight despite intravenous analgesia. His pulse in both feet became feeble and renal and hepatic function worsened. Compartment syndrome was suspected and orthopaedic surgery was consulted. He had an emergency fasciotomy of all compartments and in all four limbs. Post-procedure pulse oximetry of digits and toes had a 99% saturation, but peripheral pulses remained weak. He was able to move fingers of both hands, but had no movement of his ankles and toes. The patient was transferred to the intensive care unit (ICU) for further management. His maintenance intravenous fluid was changed to 0.9% sodium chloride due to persistent hyponatremia. His wounds were re-explored and debrided on the fifth post-operative day. Wounds culture were growing pseudomonas aeruginosa that was treated with Meropenam according to the sensitivity. Six sittings of wound debridement and irrigation were performed. Over two weeks his renal function, liver function, and serum sodium concentration normalised (Table 1) without requiring renal replacement therapy. He was transferred to the ward on day 16 and discharged home to be followed in outpatient clinic. Conclusion: Physical exercise in the presence of hyponatremia can cause rhabdomyolysis and compartment syndrome of all extremities leading to multi-organ failure.