Understanding Rhabdomyolysis Symptoms and Treatment

Rhabdomyolysis (rhabdo) occurs when there is a breakdown of skeletal muscle because of injury. Damaged muscles release proteins into the blood, which can harm the kidneys. Symptoms include severe muscle cramps, dark urine, and feeling very weak and tired. Common causes of rhabdo are performing manual labor in hot environments, doing high intensity workouts, and sustaining a traumatic injury to the muscle, such as from a fall or being crushed.

Treatment includes rest and sometimes IV hydration. Treatment needs to start as soon as possible to reduce the risk of permanent damage to the heart and kidneys.

Read on to learn more about rhabdo and what it does to the body. This article also covers symptoms to watch for, the causes of rhabdo, and how to prevent it. You can also learn about diagnosis, treatment, and potential complications.

Rhabdo is a serious medical condition that can cause permanent organ damage and is sometimes fatal. Early recognition and treatment significantly reduce the chance of permanent damage.

Muscles contain proteins and electrolytes. When a physical force or overuse damages the muscle, it releases a large amount of these proteins and electrolytes into the bloodstream. The main protein is myoglobin. While circulating in your blood, myoglobin and electrolytes can permanently damage your heart and kidneys.

According to the Centers for Disease Control and Prevention (CDC), symptoms may be subtle at first and go unnoticed. With increasing muscle breakdown, however, the symptoms will worsen. Symptoms can include:

• infrequent urination
• dark yellow urine
• feeling very weak and tired
• achy and stiff muscles
• muscle cramps
• muscles that are tender to the touch
• nausea

Seek medical care immediately if you notice these symptoms to reduce the risk of kidney damage. Call 911 or ask someone else to call if you are unable to.

Rhabdo is the result of muscle injury, which can occur in multiple ways. These include direct trauma, overexertion, infection, chemical imbalances, drugs or toxins, and genetic anomalies.

The following summary of causes comes from a 2022 review article on rhabdomyolysis except where noted.

Causes in this category include:

• crush or trauma injuries
• being immobilized for long periods
• an electric shock or lightning strike
• burns
• high intensity, strenuous exercise, particularly in people not used to it
• becoming overheated, according to the CDC

Learn more about heatstroke risk factors and prevention here.

Conditions that can increase the chance of rhabdo include:

• severe diabetic acidosis with coma
• sickle cell anemia
• certain autoimmune conditions, such as dermatomyositis

Medications, drugs, and supplements that can increase the chance of rhabdo include (but are not limited to):

• statins
• daptomycin
• corticosteroids
• diuretics
• anticholinergics
• cocaine
• ecstasy
• amphetamines
• supplements for enhancing performance or weight loss

Infections that can increase the chance of rhabdo include:

• MRSA
• malaria
• HIV
• Salmonella
• influenza
• sepsis

Other possible causes of rhabdo may include:

• severe dehydration
• electrolyte imbalance
• near drowning
• hypothermia
• frostbite
• poisoning, such as from venom exposure due to a hornet or snakebite
• mushroom poisoning
• carbon monoxide poisoning

Rhabdo is not common. In the United States, there are approximately 25,000 reports of rhabdo per year. Anyone at any age can experience it, but it is more common in adults.

People in certain professions have a higher risk of experiencing rhabdo because their job requires physical exertion in sometimes hot environments. These professions include:

• firefighting
• search and rescue (first responders)
• law enforcement
• farm work
• construction
• armed forces
• sports

Below are some steps to take on an individual and employer level to help prevent rhabdo.

To prevent rhabdo, you can:

• Be aware that physical exertion in a hot environment increases your chance of rhabdo.
• Learn the symptoms of heat-related illness.
• Take frequent rest breaks in the shade.
• Stay hydrated.
• Avoid alcohol when working hard or playing in the heat.
• Know what level of activity your body can handle.
• Avoid exerting yourself when you have an infection or symptom flare-up from another condition.

For professions that carry an increased chance of rhabdo due to heat and overexertion, employers can implement a plan of action to decrease the risk of heat-related illness in the workplace. Tips include:

• Increase break times spent in a cool environment.
• Have water stations.
• Educate employees about heat-related illnesses and rhabdo.
• Have a buddy system so that everyone has someone looking out for them.
• Encourage employees to seek medical care when they experience symptoms of rhabdo.
• Encourage employees to take sick leave when not feeling well.

If you suspect that you may have rhabdo, seek medical care as soon as possible to prevent permanent damage to your kidneys. The classic symptoms are muscle pain, weakness, and dark urine, but you may not have all three.

Do not try to diagnose yourself or determine the seriousness of your or a companion’s condition.

Your healthcare professional will ask you questions about your recent activities leading up to your symptoms and go over your health history. They will also perform a physical exam, check your vital signs, and order certain tests. These tests may include:

• a blood test to measure muscle injury by creatine phosphokinase (CPK) level
• a blood test to measure electrolytes
• an electrocardiogram to evaluate your heart
• a urine test to measure myoglobin level

CPK is an enzyme mainly present in your muscles. When you have muscle damage, the CPK level in your blood will rise. A level that is at least five times the top normal range is considered rhabdo.

The goal of treating rhabdo is to prevent injury to your kidneys. The underlying cause of the rhabdo must also be treated.

Resting and drinking plenty of fluids may be sufficient for mild rhabdo. Also, recline in a comfortable position for your muscles.

If you have moderate or severe rhabdo, you will likely need care in a hospital or another medical facility. Most of the time, a healthcare professional will start an IV line to rehydrate you and help your body excrete the proteins and electrolytes that have built up. Depending on your electrolyte levels, the doctor may also prescribe medications to help increase or decrease them.

They will also continue to draw blood samples at regular intervals to check your blood counts, kidney function, electrolyte levels, and CPK level.

If you already have severe kidney damage, you may need dialysis to help filter your blood.

Prompt treatment helps reduce the risk of kidney damage. People with acute kidney injury from rhabdo can also have a positive outlook with a full recovery.

Usually, people with a mild case can get back to their regular life within a few weeks.

Possible complications include:

• kidney failure that requires lifetime dialysis
• compartment syndrome
• certain heart conditions, such as arrhythmia

Rhabdomyolysis, or rhabdo, refers to the breakdown of muscle tissue because of damage to the muscles. It can be a serious condition if it is not treated quickly.

Symptoms include muscle pain, dark urine, and fatigue.

Treatment needs to start right away to prevent permanent damage to your kidneys. Outcomes can be positive with adequate hydration and other supportive treatments.