Myoglobin urine test

Definition

The myoglobin urine test is done to detect the presence of myoglobin in urine.

Myoglobin can also be measured with a blood test.

Alternative Names

Urine myoglobin; Heart attack - myoglobin urine test; Myositis - myoglobin urine test; Rhabdomyolysis - myoglobin urine test

How the Test is Performed

A clean-catch urine sample is needed. The clean-catch method is used to prevent germs from the penis or vagina from getting into a urine sample. To collect your urine, the health care provider may give you a special clean-catch kit that contains a cleansing solution and sterile wipes. Follow instructions exactly so that the results are accurate.

How the Test will Feel

The test involves only normal urination, which should cause no discomfort.

Why the Test is Performed

Myoglobin is a protein in heart and skeletal muscles. When you exercise, your muscles use up available oxygen. Myoglobin has oxygen attached to it, which provides extra oxygen for the muscles to keep up a high level of activity for a longer period.

When muscle is damaged, myoglobin in muscle cells is released into the bloodstream. The kidneys help remove myoglobin from the blood into the urine. When the level of myoglobin is too high, it can damage the kidneys.

This test is ordered when your provider suspects you have muscle damage, such as damage to the heart or skeletal muscle. It may also be ordered if you have acute kidney failure without any clear cause.

Normal Results

A normal urine sample does not have myoglobin. A normal result is sometimes reported as negative.

Normal value ranges may vary slightly among different laboratories. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results may be due to:

• Heart attack
• Malignant hyperthermia (very rare)
• Disorder that causes muscle weakness and loss of muscle tissue (muscular dystrophy)
• Breakdown of muscle tissue that leads to the release of muscle fiber contents into the blood (rhabdomyolysis)
• Skeletal muscle inflammation (myositis)
• Skeletal muscle ischemia (oxygen deficiency)
• Skeletal muscle trauma

Risks

There are no risks with this test.

References

Nagaraju K, Aggarwal R, Lundberg IE. Inflammatory diseases of muscle and other myopathies. In: Firestein GS, Budd RC, Gabriel SE, Koretzky GA, McInnes IB, O'Dell JR, eds. Firestein & Kelly's Textbook of Rheumatology. 11th ed. Philadelphia, PA: Elsevier; 2021:chap 90.

Selcen D. Muscle diseases. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 393.