Rhabdomyolysis affects about one out of 10,000 people in the United States, with slighter higher incidence in men. Rhabdomyolysis may result from any condition that causes damage to skeletal muscle, especially trauma. Rhabdomyolysis accounts for an estimated eight to fifteen precent of cases of acute renal failure. About five percent of rhabdomyolysis cases result in death.

Risk Factors
Common risk factors in rhabdomyolysis cases include alcohol abuse, recent soft tissue compression, and seizure activity. Other causal factors include trauma, drug abuse, metabolic derangements, hypothermia, flu-like illness, sepsis, and gangrene. Rhabdomyolysis may occur after traumatic events, such as blunt trauma, extensive burn injury, prolonged immobilization, and near electrocution and drowning. Rhabdomyolysis may also occur after excessive muscular activity, such as sporadic strenuous exercise (e.g., marathons). Rhabdomyolysis may result from a variety of viral, bacterial, and fungal infections. Toxin-related rhabdomyolysis may result from the abuse of substances like ethanol, methanol, isopropanol, heroin, methadone, barbiturates, and amphetamine. Toxin-related rhabdomyolysis may also result from prescription and nonprescription medications, including statin, which doctors use to lower cholesterol.
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Symptoms

Symptoms of rhabdomyolysis include muscle pain, weakness, tenderness, malaise, fever, dark urine, nausea, and vomiting. A person suffering from rhabdomyolysis may also experience weight gain, seizures, joint pain, and fatigue. Fluid loss and resulting electrolyte imbalance may cause agitation, confusion, and an altered mental status. The muscle pain may involve specific groups of muscles or may occur throughout the body. Most frequently the involved muscle groups include the thighs, calves and lower back; however, some patients report no symptoms of muscle injury.
The three most common symptoms are muscle weakness, myalgias (muscle pains), and dark urine. Unforutunately not all 3 symptoms are usually seen together.

Since Rhabdomyolysis has many causes it may not be obvious to the physician especially if the symptoms are subtle. However, since the disease can result in acute renal failure, doctors and patients should be alert.