Key takeaways

Rhabdomyolysis, or rhabdo, is a potentially life-threatening condition caused by the breakdown of muscle tissue releasing a protein into the bloodstream that can damage the kidneys.
Causes of rhabdo include trauma, overexercising, overheating, certain medications and illegal drugs, infections, medical conditions, and genetic disorders.
Symptoms of rhabdo are often not present but can include muscle pain, weakness, dark urine, tenderness, lethargy, nausea, and fever, with diagnosis primarily based on elevated creatine kinase levels in the blood.
Treatment focuses on aggressive hydration to flush out muscle breakdown byproducts and protect the kidneys, with prevention strategies including avoiding risk factors like intense exercise in the heat and staying hydrated.

You’ve had a long year through the pandemic. Now, summer is here, your favorite places are opening back up, and you’re ready to get back to your old routine. It’s time to ramp up your workouts and stop spending so much time on the couch.

Getting exercise and moving your body throughout the day have some great benefits for your health. But there’s a dangerous side effect of that intense new exercise routine that you might not have heard of. It’s called rhabdomyolysis and it can potentially be life-threatening if it’s left untreated. Learn how to keep yourself safe from this concerning muscular condition.

What is rhabdomyolysis?

Rhabdomyolysis, or rhabdo for short, happens when your skeletal muscle tissue breaks down and muscle cells are released into your bloodstream. Injured muscle fibers release a protein called myoglobin—which is similar to hemoglobin and stores oxygen in muscles. When it leaks into your blood, it filters through the kidneys and can damage the cells within.

Rhabdo is relatively uncommon. About 26,000 people in the United States get it every year. But because you could get rhabdo and not show any symptoms, that number could be higher. You have an increased risk for rhabdo if you’re:

Male, especially if you have larger muscle mass
Of African American descent
Overweight or obese on the body mass index (BMI)
A smoker
Taking antipsychotics or a statin medication

Causes

There are several different ways you could get rhabdo, including some that you may not expect to cause muscle injury.

1. Trauma

A trauma such as a crush injury to your leg can cause muscle damage and is the most common reason someone might get rhabdo. For example, rhabdo may develop after someone has their leg pinned after a car accident.

2. Overexercising

When you perform exercises that can potentially overexert your body, such as running a marathon, practicing gymnastics, or even taking spin classes (as one 2017 study indicated), you can injure your muscles and cause breakdown.

3. Overheating

Working in a strenuous physical job, such as with firefighters and construction workers, can put you at risk for rhabdo. So can working out in the heat. When your body temperature is out of control (hyperthermia), it puts extra stress on your system, and can lead to exertional rhabdomyolysis. Anytime you’re at risk for heat stroke, you could also be at risk for rhabdo.

4. Medications or Illicit drug use

“Most illicit drugs make you prone to rhabdo as well as several prescription and over-the-counter (OTC) medications,” explains Jared Ramsey, DO, a primary care sports medicine doctor with Allegheny Health Network in Grove City, Pennsylvania. These can include:

Statins such as Lipitor (atorvastatin)
Weight-loss medications
Non-steroidal anti-inflammatory drugs (NSAIDS), such as ibuprofen
Medications such as anticholinergics and antihistamines that can affect your body’s temperature regulation
Certain supplements such as creatine
Amphetamines
Cocaine, PCP, or heroin
Opioids
Excessive alcohol or caffeine intake
Toxins such as snake or spider bites, or wasp stings

“Some of our worst rhabdomyolysis cases involve patients who overdose on an opioid, such as fentanyl, and lay on a hard surface for a prolonged period,” says J. David Gatz, MD, assistant medical director of the Adult Emergency Department for the University of Maryland Medical Center.

5. Infection

Certain infections can cause rhabdo such as:

Influenza
Human immunodeficiency virus (HIV)
Strep
Epstein-Barr virus that can cause mono

6. Medical conditions

Some medical conditions cause rhabdo to occur more easily including:

Seizures and tremors, such as those from alcohol withdrawal
Neuroleptic malignant syndrome, a reaction that can occur with antipsychotic medications
Endocrine disorders such as hypothyroidism and diabetic ketoacidosis
Autoimmune conditions such as dermatomyositis

7. Genetic disorders

Certain conditions that run in your family can make you more prone to rhabdo. These could include:

Sickle-cell disease or having the trait for it
Duchenne and Becker muscular dystrophies
Familial malignant hypothermia, a condition you inherit that can cause significant health issues with certain anesthesia medications during surgery

Symptoms

Muscle pain, weakness, and dark urine are the three classic symptoms of rhabdomyolysis. Interestingly, these signs are only present in less than 10% of people. According to Dr. Ramsey, muscle pain is even less common than muscle weakness and dark urine and only about half of people with rhabdo will have pain in their muscles.

With rhabdo, you might also experience:

Muscle soreness and pains
Tenderness
Feeling lethargic
Malaise, or a general feeling you’re not well
Nausea and/or vomiting
Fever
No symptoms at all

The symptoms of rhabdo could also mimic other health conditions. Dr. Gatz explains the biggest clue that you may be dealing with rhabdo and not something else, will be how your symptoms occurred. If you’ve recently been working out hard, perhaps even training in a hot environment, and you’re suddenly noticing these symptoms in your body, odds are you may have rhabdo.

Diagnosis

“It’s always appropriate to see a doctor if you’re concerned you have rhabdomyolysis,” says Dr. Gatz, because “while many cases are minor, there can be severe complications.” In fact, 10% to 40% of people with rhabdo will develop acute renal failure (ARF), where kidneys build up waste products and can’t filter these out properly. It may be recommended you see a nephrologist, a provider that specializes in the kidneys, for treatment and follow up.

You should be seen in an emergency department if you are experiencing symptoms of rhabdo and have had:

Significant pain
A traumatic injury
Had exposure to a toxin
Have any concern that something is wrong

However, if symptoms are more minor, in cases of over-exerting yourself, Dr. Gatz explains that you could be seen initially in urgent care for a workup and treatment.

Ultimately, whatever healthcare facility you’re seen at, your provider will want to perform a blood test called creatine kinase (CK) which is an enzyme that is present in your skeletal muscles. If this level is elevated, it can confirm a diagnosis of rhabdomyolysis.

Complications of rhabdomyolysis include acute kidney injury, kidney damage, and even kidney failure, so you may also have blood and urine tests to check for kidney dysfunction. Since myoglobin and electrolytes such as potassium, can leak into the blood as well, your provider will probably check for these, along with your creatinine levels, a muscle-breakdown byproduct.

Treatment

If you think you may have rhabdo, don’t wait to address it. Rhabdo usually goes away in a few days and you can make a full recovery if you get treatment early. Only your healthcare provider can tell you how severe your rhabdo is and what treatment you should receive.

The best treatment for rhabdo is fluids. “Aggressive hydration is the mainstay of treatment. Often, large amounts of (intravenous) IV fluids are needed to wash out the muscle breakdown and protect the kidneys,” explains Dr. Gatz.

For more mild cases of rhabdomyolysis, or if you have symptoms that are vague, make sure you’re drinking plenty of fluids and follow up with your provider in the next day or two if you aren’t feeling better, adds Dr. Ramsey. Rest, and avoid the heat as much as you can.

Pain medications can be taken if needed, but it would be a good idea to consult with your healthcare provider before you treat yourself with over-the-counter pain medications.

If you have dangerous electrolyte imbalances, you may need an IV treatment. Bicarbonate and certain diuretics, such as Mannitol, may be given to help improve your kidney function and can also treat abnormal electrolyte levels. Surgery might be necessary such as in cases of compartment syndrome.

If left untreated and the damage to your kidneys is significant, you may need dialysis until your kidneys are healthy again. If your kidneys don’t recover, lifetime dialysis or a kidney transplant may be needed.

How to prevent rhabdomyolysis

Unfortunately, in certain cases, there’s not much you can do if you get rhabdo. But you can take precautions when it comes to exercising to make sure you can prevent rhabdo from occurring and take care of your body, according to Dr. Ramsey.

Avoid risk factors such as working out in the heat, exercising too intensely, or becoming dehydrated. “Those who are at the highest risk are individuals working out in a warm setting that are just starting a new exercise program or are greatly increasing their intensity,” says Dr. Ramsey.

If you are starting a new workout routine, want to ramp up your exercise regiment, or have a physically demanding job, make sure you’re drinking plenty of fluids, wear loose breathable clothing such as cotton, and start out in a cool environment.Take breaks every hour and increase your workout intensity slowly.

You may not think that getting sick with the flu can cause you to develop rhabdo, but if you are ill, stay home from school or work. Try avoiding unnecessarily excessive use of over-the-counter NSAIDs, which can appreciate rhabdo.

The most common reason you might be getting rhabdo repeatedly is due to:

Exercising in the heat
Exercising too intensely
Becoming dehydrated

Don’t let worries about rhabdo prevent you from exercising regularly. But it’s good to pay attention to how your body is feeling and if you’re overexerting yourself. Take breaks, stay cool, and drink fluids. And don’t hesitate to inform your healthcare provider if you have any concerns.