Myoglobin (Urine)

Urine myoglobin

This test measures a protein called myoglobin in your urine. The test can help find out if your muscle tissue has been injured.

Myoglobin is found in your heart and skeletal muscles. There it captures oxygen that muscle cells use for energy. But when you have a heart attack or severe muscle damage, myoglobin is released from the muscle into your blood. Once there, it can rise to dangerous levels in your body.

Your kidneys filter your blood for myoglobin so that it can be removed from your body in your urine. But too much myoglobin can overwhelm the kidneys and lead to kidney failure. In some cases, this test can help your healthcare provider find the hazard and protect your kidney health.

You may need this test if your healthcare provider believes that you have a severe muscle injury. Symptoms vary, depending on the cause of muscle damage. They may include:

• Fever

• Fast heart rate

• Nausea and vomiting

• Belly pain

• Muscle pain, stiffness, or cramping

You may also have this test if you have serious muscle pain, weakness, and dark brown or reddish urine. These are possible signs of rhabdomyolysis, a potentially life-threatening muscle condition that can cause your kidneys to fail. Some cases are tied to the use of statins, a group of cholesterol-lowering medicines, or can be connected to intense exercising.

If your myoglobin level rises too high, you may have to get IV (intravenous) fluids or other treatments to help flush the extra myoglobin out of your body. This test will help your healthcare provider find out if your injuries need treatment right away.

You may also need other tests. These include:

• Complete blood count, including a differential and platelet count

• Blood urea nitrogen; creatinine; and routine electrolytes, including potassium

• Calcium, phosphate, albumin, and uric acid

• Creatine phosphokinase  

• Urinalysis

Test results may vary depending on your age, gender, health history, and other things. Your test results may be different depending on the lab used. They may not mean you have a problem. Ask your healthcare provider what your test results mean for you.

Normal results show little or no myoglobin in your urine.

If your results are higher, it may mean you have muscle injury. These are some possible causes of muscle injury:

• Coma or another situation in which you don't move

• Surgery

• Certain infections

• Poisons and certain medicines

• Inherited conditions that cause muscle problems

• Abnormally strenuous exercise

• Crushing injury, such as from a car accident

This test is done with a urine sample. Your healthcare provider will tell you how to collect it.

This test poses no known risks.

Other factors aren't likely to affect your results.

You don't need to get ready for this test. But be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illegal drugs you may use.