What is rhabdomyolysis?

Rhabdomyolysis is a serious condition caused by muscle injury. It leads to muscle weakness, pain and swelling.

When muscle tissue gets seriously injured, it breaks down, releasing the chemicals from the muscle — including a protein called myoglobin — into the bloodstream. This can worsen kidney function and cause kidney failure. It can also change the balance of electrolytes (minerals and salts) in the body, which can lead to serious problems with the heart and other organs. This can be life threatening in not treated urgently.

What are the symptoms of rhabdomyolysis?

Rhabdomyolysis symptoms will change based on the cause, but include:

• intense muscle aching or swelling
• muscle weakness or stiffness
• feeling generally exhausted
• dark red or brown urine, or very little or no urine
• fever
• nausea and vomiting

What causes rhabdomyolysis?

Rhabdomyolysis is caused by an injury to muscle tissue or following extreme exercise, such as running a marathon or doing high-intensity resistance training such as cross-fit. Other causes of rhabdomyolysis include the following:

Medicines and other substances

• taking illegal drugs such as cocaine, amphetamines or heroin
• a side effect of some medicines, such as cholesterol-lowering drugs (statins) or amphetamines used for ADHD — although the risk is very low
• drinking too much alcohol
• being bitten or stung by wasps, hornets or snakes

Trauma and exercise

• extreme muscle use, for example, running marathons or improper resistance training
• trauma or crush injuries, for example, from a car accident
• pressure on your muscles for a long time, for example when someone is lying unconscious on a hard surface

Illnesses

• very high body temperature (hyperthermia) or heat stroke
• having a seizure
• severe infections
• some genetic, autoimmune and muscular dystrophy conditions

You are at greater risk of rhabdomyolysis if you are an older adult, have diabetes, take part in extreme sports or use a lot of drugs or alcohol.

How is rhabdomyolysis diagnosed?

Your doctor will ask you about your symptoms and do an assessment. You will also need blood tests and urine tests. Rhabdomyolysis is often diagnosed in hospital.

How is rhabdomyolysis treated?

Rhabdomyolysis is usually treated in hospital through an intravenous (IV) drip. The fluids help your body produce enough urine and prevent kidney failure. You many need medicine to correct the electrolyte (mineral and salt) imbalance in the blood. Any medicine that would be a risk factor for rhabdomyolysis is stopped.

In rare cases, dialysis is needed. A dialysis machine is used to filter your blood to remove the harmful chemicals and high levels of electrolytes. It then returns the filtered blood back to your veins. You will only need dialysis if your kidneys aren’t working well enough to filter your blood.

You may need urgent surgery to avoid more muscle death or nerve damage, for example if you have compartment syndrome. This syndrone is where too much pressure builds up in the injured group of muscles (compartment) and stops blood flow to and from the affected body tissues.

Early diagnosis and treatment of rhabdomyolysis and its causes increases your chances of a full recovery.

Rhabdomyolysis complications

If not treated early, rhabdomyolysis can lead to complications, such as:

• very high electrolyte (mineral and salt) levels in the blood which can lead to an irregular heartbeat or your heart stopping (cardiac arrest)
• kidney failure
• bleeding and clotting problems
• compartment syndrome

How is rhabdomyolysis prevented?

You can’t prevent all causes of rhabdomyolysis, especially if you have an underlying health condition, or if you have an accident.

You can reduce risk of developing rhabdomyolysis by:

• staying hydrated and avoid getting overheated — take breaks in the shade if you’re doing physical activity in the heat
• avoiding addictive substances alcohol and drugs
• talking to your doctor about any medicines you’re taking that may increase your risk of developing rhabdomyolysis

You can prevent exercise-induced rhabdomyolysis. It is important to gradually build up when you start resistance training. Start slowly and gently increase the load to prevent rhabodomyolysis. When you are starting resistance training, it’s best to seek advice from an exercise professional. Start with training loads of 60–70% for 8 to 12 repetitions. Don’t do more than 1 to 3 sets per exercise when you start working out.

Read more on how to start strength training in a safe way.

When should I see my doctor?

If you have symptoms of rhabdomyolysis such as muscle pain, stiffness, swelling or changes to your urine, see your doctor urgently if:

• you have been doing resistance exercise
• you take a medicine that puts you at risk of rhabdomyolysis, such as a statin

If you are concerned about taking a statin, speak with your doctor or pharmacist before stopping suddenly or changing your dose.

Before starting any new resistance exercise routine, it is best to speak to your doctor about a safe way to start and how to build up.

Resources and support

If you are concerned about muscle pain, but it is not an emergency, you can call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.

Read the fact sheet on statin safety.

To learn how to get fit safely visit Fitness Australia.