Common causes include muscle injury and impaired blood flow in damaged tissue, drugs, toxic substances, and infections.
Less common causes include electrolyte imbalances, endocrine and genetic disorders, extreme exercise, and extremes in body temperature.
Symptoms can include muscle pain, weakness, and reddish-brown (or tea-colored) urine, but most people do not have all of these symptoms.
Serious complications include acute kidney injury (also called acute kidney failure).
Diagnosis is with blood and urine tests.