Severe cases of rhabdomyolysis often result in myoglobinuria, a condition wherein the myoglobin from muscle breakdown spills into the urine, making it dark, or “tea colored” (myoglobin contains heme, like hemoglobin, giving muscle tissue its characteristic red color). This condition can cause serious kidney damage in severe cases. The injured muscle also leaks potassium, leading to hyperkalemia, which may cause fatal disruptions in heart rhythm. In addition, myoglobin is metabolically degraded into potentially-toxic substances for the kidneys. Massive skeletal muscle necrosis may further aggravate the situation, by reducing plasma volumes and leading to shock and reduced bloodflow to the kidneys.