This test measures a protein called myoglobin in your urine. The test can help find out whether your muscle tissue has been injured.
Myoglobin is found in your heart and skeletal muscles, where it captures oxygen that muscle cells use for energy. But when you have a heart attack or severe muscle damage, myoglobin is released 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 doctor detect the hazard and protect your kidney health.
You may need this test if your doctor suspects that you have a severe muscle injury. Symptoms vary, depending on the cause of muscle damage, but may include:
Nausea and vomiting
You may also have this test if you have serious muscle pain and 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 associated with the use of statins, a group of cholesterol-lowering drugs.
If your myoglobin level rises too high, you may have to get intravenous fluids or other treatments to help flush the excess myoglobin out of your body. This test will help your doctor find out whether your injuries need treatment right away.
Your doctor may also order other tests, including:
Complete blood count, or CBC, including a differential and platelet count
Blood urea nitrogen, or BUN; creatinine; and routine electrolytes, including potassium
Calcium, phosphate, albumin, and uric acid
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
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
Poisons and certain medications
Inherited conditions that cause muscle problems
Unusually strenuous exercise
This test requires a urine sample. Your doctor 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 prepare for this test. But be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.