Rhabdomyolysis is the breakdown of damaged skeletal muscle.
Muscle breakdown causes the release of myoglobin into the bloodstream. Myoglobin is the protein that stores oxygen in your muscles. If you have too much myoglobin in your blood, it can cause kidney damage.
About 26,000 cases of rhabdomyolysis are reported in the United States each year. Most people with rhabdomyolysis are treated with fluids given through their veins in an intravenous (IV) drip. Some people may require dialysis or hemofiltration to address kidney damage in more severe cases.
Recognizing the symptoms
The initial symptoms of rhabdomyolysis can be subtle. They’re not specific and may mimic other conditions. The symptoms of rhabdomyolysis include:
- muscle weakness
- low urine output
- dark, tea-colored urine
- infrequent urination
- a fever
- a sense of malaise, or feeling sick
What causes rhabdomyolysis?
Rhabdomyolysis is always triggered by muscle injury. This injury can have physical, chemical or genetic causes. Anything that damages the muscles can cause this condition. Possible causes include the following:
Trauma, heat, and exertion
Causes in this category include:
- a crush injury, which can occur when something heavy falls on you
- a heatstroke
- a third-degree burn
- blocked blood vessels
- a lightning strike
- intense shivering
- an ischemic limb injury, which occurs when your tissue lacks an adequate blood supply
- pathological muscle exertion
- a car accident
- intense exercise, such as marathon running
Genetic and metabolic disorders
Some people develop rhabdomyolysis because of genetic conditions such as problems with metabolism of
- lipids, or fats
- purines, which are in certain foods, such as sardines, liver, asparagus
Metabolic problems, such as the following, can also trigger rhabdomyolysis:
- hypothyroidism or low thyroid hormone levels
- diabetic ketoacidosis, or a buildup of ketones in the body
- electrolyte imbalances
Genetic disorders that can lead to rhabdomyolysis include:
- a carnitine deficiency
- McArdle’s disease
- a lactate dehydrogenase deficiency
- Duchenne muscular dystrophy
Infection and inflammation
Many types of infection and inflammation can cause rhabdomyolysis, including:
- viral infections
- bacterial infections
Medications and toxins
One important cause of rhabdomyolysis is statin medications, which are cholesterol-lowering drugs that many people take. Statins include:
Although rhabdomyolysis only occurs in a few people who take statins, so many people take these medications that it’s important to be aware of the risk.
The condition can also occur due to exposure to other drugs, certain toxins, and high levels of alcohol. Other drugs that can cause rhabdomyolysis include:
Many other potential causes exist in these four categories beyond the ones listed.
How is rhabdomyolysis diagnosed?
Your doctor will look and feel the larger skeletal muscles in your body, especially any that ache, to check for tenderness. They may also perform urine and blood tests to confirm a diagnosis of rhabdomyolysis.
Tests to determine muscle and kidney health may include determining levels of:
- creatine kinase, which is an enzyme found in the skeletal muscles, the brain, and the heart
- myoglobin in blood and urine, which is a protein that’s a byproduct of muscle breakdown
- potassium, which is another important mineral that may leak from injured bone and muscles
- creatinine in blood and urine, which is a breakdown product created by muscle that’s normally removed from the body by the kidneys
Elevated levels of these substances are signs of muscle damage.
Treatments options for rhabdomyolysis
If discovered early in its progression, rhabdomyolysis can be successfully treated without long-term damage to the kidneys.
Getting enough fluid into your body is the first and most important treatment. They must start IV fluids quickly. This fluid should contain bicarbonate, which helps flush the myoglobin out of your kidneys.
Your doctor may prescribe medications such as bicarbonate and certain kinds of diuretics to help keep your kidneys functioning.
They can also treat high potassium levels in the blood, or hyperkalemia, and low blood calcium levels, or hypocalcemia, with appropriate IV fluids.
If kidney damage and acute renal failure have already started, you may need to receive dialysis. During dialysis, blood is taken out of the body and cleaned in a special machine in order to remove waste products.
In mild cases of rhabdomyolysis, home treatment can help aid in the recovery process. The goals of at-home treatment include resting the body so muscles can recover and rehydration to help prevent further kidney damage.
When you’re feeling fatigued, recline in a comfortable position and try to relax. Drink plenty of water and other clear liquids, such as light broth and sports drinks.
Your long-term outlook depends on the degree of kidney damage. If rhabdomyolysis is caught early, you may be able to avoid major complications and return to normal health in a few weeks. Even then, however, you may still have some lingering weakness and pain in your muscles.
If major kidney damage occurs, your kidneys may be permanently damaged.
Several of the symptoms and complications of rhabdomyolysis are serious and may result in death if you don’t get treatment for them.
Tips for preventing rhabdomyolysis
You can prevent rhabdomyolysis by drinking plenty of fluids before and after strenuous exercise. This will dilute your urine and help your kidneys eliminate any myoglobin that your muscles may have released during exercise.
If you have an existing degenerative muscle condition or have sustained damage to your muscle after a recent trauma, you can prevent rhabdomyolysis by staying well-hydrated at all times. Carry a full refillable water bottle with you at all times so you can make sure you’ll have access to something to drink. Drink whenever you begin to feel thirsty, and don’t wait until your thirst increases.
See your doctor when you suspect you may be sick or have an infection. Addressing illness as soon as possible can help prevent the muscle damage that may lead to rhabdomyolysis.