Rhabdomyolysis symptoms: What are the early signs of rhabdomyolysis?

Medically reviewed by Anne JacobsonMD, MPH
Board-Certified Family Physician
Updated Oct. 27, 2023  •  Published Jun. 20, 2023
Fact Checked
 Symptoms of rhabdomyolysis

Overview: What does rhabdomyolysis look like?

Rhabdomyolysis (“rhabdo”) is the rapid breakdown of skeletal muscle tissue due to injury, overexertion, infections, heat stroke, drug side effects, or poisons. When muscle tissues die quickly, a cascade of problems follows when their contents spill into the bloodstream. These problems include kidney damage, electrolyte imbalances, blood clots, acidosis, heartbeat irregularities, and severe localized swelling. The worst cases of rhabdo can be fatal. The classic signs of rhabdomyolysis are muscle pain, weakness, and tea-colored urine, though most people won’t experience all these symptoms. The muscle pain usually hurts more than typical soreness and doesn’t improve in just a few days. It may get so bad that moving the affected muscle is hard. The area around the damaged muscle may swell, bruise, or become tender. Because of toxins circulating in the bloodstream, it’s possible to develop a fever, feel nauseous, or start throwing up. People may become confused, agitated, or even delirious in severe cases. If the kidneys are damaged, urine slows to a trickle or stops altogether. If that happens, the death rate can be as high as 50%.

Key takeaways:

  • Rhabdomyolysis is an uncommon health condition that can affect anyone regardless of age, sex, race, or ethnicity. 

  • Early signs of rhabdomyolysis include severe muscle pain, weakness, and dark-colored urine.

  • Symptoms of rhabdomyolysis require immediate medical attention.

  • Rhabdomyolysis is most commonly caused by muscle injuries (particularly crush injuries), sepsis, immobilization, and cardiovascular surgery. Other causes of rhabdomyolysis include over-exercise, fractures, high-voltage electrocution, severe burns, medication side effects, viral infections, electrolyte imbalances, poisoning, venomous bites or stings, body temperature extremes (hyperthermia, hypothermia, frostbite), hormone disorders, genetic disorders, and muscle disorders. You may be at risk for developing rhabdomyolysis if you drink a lot of alcohol, take illicit drugs or certain prescription medications, exercise heavily, work or exercise when it is hot or humid, are an endurance athlete, are immobilized for long periods, have Duchenne muscular dystrophy, or take weight loss or performance supplements.

  • Rhabdomyolysis requires a medical diagnosis.

  • Rhabdomyolysis requires treatment. Rhabdomyolysis symptoms and complications typically resolve with treatment within variable timeframes, depending on the severity of the condition and its complications. Full recovery may not always be possible, and severe rhabdomyolysis has a high fatality rate.

  • Treatment of rhabdomyolysis may include treatment of the underlying cause, fluid resuscitation, dialysis, electrolyte imbalance treatments, and treatments specific to complications. Read more about rhabdomyolysis treatments here.

  • Untreated rhabdomyolysis could result in complications like acute kidney injury, electrolyte imbalances, heartbeat abnormalities, cardiac arrest, kidney failure, blood clotting, metabolic acidosis, and severe muscle swelling (compartment syndrome).

What are the early signs of rhabdomyolysis?

The early signs of rhabdomyolysis include:

  • Muscle pain, usually severe

  • Dark urine

  • Weakness

Other rhabdomyolysis symptoms

Common symptoms of rhabdomyolysis include:

  • Muscle pain

  • Muscle tenderness or soreness

  • Weakness

  • Swelling

  • Bruising

  • Dark urine (tea-colored or cola-colored)

Other symptoms may be due to complications of rhabdomyolysis including:

  • Fever

  • Feeling bad (malaise)

  • Nausea

  • Vomiting

  • Decreased urination

  • Mental changes such as agitation, confusion, or delirium

  • Heartbeat abnormalities (arrhythmias)

Rhabdomyolysis vs. inflammatory myopathy

Inflammatory myopathy (or myositis) is a set of rare autoimmune conditions that can cause many of the same symptoms as rhabdomyolysis but without the same health-threatening complications. Both conditions are uncommon, but people with recurrent rhabdomyolysis may be tested to see if they have inflammatory or metabolic myopathy. 

The key difference between the two conditions is that rhabdomyolysis is an immediate, urgent medical condition, while inflammatory myositis is chronic and long-lasting. The most characteristic symptom of autoimmune myositis is muscle weakness, whereas muscle pain is the most common symptom of rhabdomyolysis. 

Rhabdomyolysis Myositis
Shared symptoms
  • Muscle pain
  • Muscle weakness
  • Swelling
Unique symptoms
  • Dark-colored urine
  • Muscle tenderness
  • Fever
  • Nausea
  • Vomiting
  • Little or no urine
  • Mental changes
  • Heartbeat abnormalities
  • Fatigue
  • Difficulty climbing stairs, standing up, or raising the arms
  • Trouble swallowing or breathing
  • Rash

RELATED: 7 causes of muscle aches

When to see a doctor for rhabdomyolysis symptoms

Rhabdomyolysis is a potentially serious condition, so get immediate medical care if muscle pain is severe or doesn’t improve over a few days. If urine turns dark, that’s a clear sign that emergency medical treatment is needed. If an immediate appointment with a healthcare professional is not available, go to an urgent care or emergency room. The chances of a full recovery decline the longer treatment is delayed. The best time frame is to get treatment within 12-24 hours of the appearance of symptoms before the kidneys are damaged. Approximately 15% to 33% of rhabdomyolysis cases result in acute kidney injury, a potentially fatal complication. 

Healthcare providers diagnose rhabdomyolysis primarily based on risk factors, symptoms, blood tests, and urine tests. The blood tests will show many of the chemical markers of muscle damage, such as high creatine kinase levels (CK levels), kidney dysfunction, electrolyte imbalances, uric acid buildup, and acidosis. Urine tests will confirm the diagnosis by detecting the presence of myoglobin. An electrocardiogram will help identify any effects on the heart. The clinician may also test blood clotting time to spot any possible blood clot issues.

Identifying the cause will require a thorough medical history and further blood tests, toxicology tests, or CT or MRI scans. A muscle biopsy performed after the crisis has passed can help spot any underlying muscle disease.

Complications of rhabdomyolysis

Rhabdomyolysis complications can be severe and life-threatening. They include:

  • Acute kidney injury or failure

  • Electrolyte imbalances including

    • High potassium (hyperkalemia)

    • Low calcium (hypocalcemia)

    • High phosphate (hyperphosphatemia)

    • High calcium (hypercalcemia) - during recovery phase

  • Dehydration

  • Disseminated intravascular coagulation (abnormal blood clotting and bleeding throughout the body)

  • Uric acid buildup

  • Metabolic acidosis (elevated blood acid levels)

  • Heart rhythm abnormalities

  • Severe muscle swelling (compartment syndrome)

  • Liver swelling

  • Cardiac arrest

How to treat rhabdomyolysis symptoms

People with rhabdomyolysis should expect to be hospitalized, but this may not always be true. Seniors with rhabdomyolysis are likely to be admitted into an intensive care unit (ICU) to allow for close monitoring.

When treating rhabdomyolysis, healthcare providers are intent on preventing complications with:

  • IV fluid resuscitation to prevent kidney injury, normalize electrolytes , and flush out myoglobin

  • Hemodialysis in cases of kidney failure

  • Treatment of the underlying condition

  • Treatment of complications

Compartment syndrome is a serious complication that can destroy an entire muscle group and rapidly damage the kidneys. Muscles, along with blood vessels and nerves, are grouped in compartments covered with a tough, inflexible membrane. In compartment syndrome, swelling inside that muscle compartment can build up until the tissues inside start dying off. In cases of compartment syndrome, emergency surgery is required to cut into the compartment and decompress the area.

In mild rhabdo cases that occur in young, otherwise healthy people, the condition may be treated at home with oral hydration and rest after being evaluated by a healthcare professional.

Once an acute rhabdomyolysis crisis has passed, further treatment may still be necessary, such as physical therapy or dialysis.

Signs rhabdomyolysis is getting better

Rhabdomyolysis gets better when the bloodstream contains normal levels of electrolytes, creatinine phosphokinase, and myoglobin—in other words when muscle tissues stop dying. The only way to know is through blood and urine tests, which are performed regularly during treatment. Symptom relief, recovery of muscle function, or the resolution of complications may take a few weeks. Some complications may not fully resolve. 

Most importantly, get medical help

When rhabdomyolysis symptoms are treated early, a full recovery is the most likely outcome. The longer rhabdomyolysis goes on, the more likely a person will experience severe and even life-threatening complications such as kidney damage or compartment syndrome.

In some cases, these complications may cause chronic problems or disability long after the rhabdomyolysis is cured. Get immediate medical care if muscle pain is severe, has no explanation, doesn’t get better, or the urine turns dark. If muscle pain follows hard

FAQs about rhabdomyolysis symptoms

How does rhabdomyolysis affect the kidneys?

Muscle breakdown causes the contents of muscle cells to empty into the bloodstream. Among those substances is myoglobin, which muscles use to store oxygen for when it’s needed. Myoglobin released from the muscles into the blood is toxic to the tiny filters in the kidneys. Excessive amounts of myoglobin can quickly harm the kidneys, usually in only a few hours, depending on the concentration. The damage can eventually cause the kidneys to fail, leaving them unable to filter water, electrolytes, and other bodily substances.

What drugs cause rhabdomyolysis?

Several drugs can cause rhabdomyolysis in some people. These include statins to treat high cholesterol, corticosteroids, the antibiotic erythromycin, the antifungal drug itraconazole, the immunosuppressant cyclosporine, and the gout medication colchicine. Cocaine, ecstasy, and high doses of amphetamines are toxic to muscle cells and can cause rhabdomyolysis. Excessive alcohol can also cause rhabdomyolysis because of prolonged immobilization. Intravenous opioid use is also associated with rhabdomyolysis.

What is the best diet for rhabdomyolysis?

While there are many good foods and drinks to help with muscle recovery, the best diet for rhabdomyolysis is to drink plenty of fluids. This will help with electrolyte imbalances and flush substances like myoglobin out of the bloodstream.

What’s next? Additional resources for people with rhabdomyolysis symptoms

Test and diagnostics

Treatments

Scientific studies and clinical trials

Medically reviewed by Anne JacobsonMD, MPH
Board-Certified Family Physician

Anne Jacobson, MD, MPH, is a board-certified family physician, writer, editor, teacher, and consultant. She is a graduate of University of Wisconsin School of Medicine and Public Health, and trained at West Suburban Family Medicine in Oak Park, Illinois. She later completed a fellowship in community medicine at PCC Community Wellness and a master's in Public Health at the University of Illinois-Chicago. She lives with her family near Chicago.

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