Myoglobin - urine

• Alternative Names

  Urine myoglobin

• How the test is performed

  A clean-catch (midstream) urine sample is needed.

  Men or boys should first wipe clean the head of the penis. Women or girls need to wash the area between the lips of the vagina with soapy water and rinse well.

  As you start to urinate, allow a small amount to fall into the toilet bowl (this clears the urethra of contaminants). Then, in a clean container, catch about 1 to 2 ounces of urine and remove the container from the urine stream. Give the container to the health care provider or assistant.

  In infants, thoroughly wash the area where urine exits the body. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on your infant. For boys, place the entire penis in the bag and attach the adhesive to the skin. For girls, place the bag over the labia. Diaper as usual over the secured bag.

  This procedure may take a couple of attempts -- lively infants can move the bag, causing the urine to be absorbed by the diaper. Check the infant frequently and change the bag after the infant has urinated into it. Drain the urine from the bag into the container provided by your health care provider.

  Deliver it to the laboratory or your health care provider as soon as possible upon completion.

• How the test will feel

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

• Why the test is performed

  Myoglobin levels may be obtained when muscle damage, including skeletal and heart muscle damage, is suspected.

• Normal Values

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

• What abnormal results mean

  The presence of myoglobin in the urine may indicate:

  • Skeletal muscle ischemia (blood deficiency)
  • Skeletal muscle trauma
  • Skeletal muscle inflammation (myositis)
  • Heart attack
  • Muscular dystrophy
  • Rhabdomyolysis
  • Malignant hyperthermia (very rare)
• What the risks are

  There are no risks.

• References

  Barohn RJ. Muscle diseases. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 447.

  O’Connor FG, Deuster PA. Rhabdomyolysis. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 114.

Review Date: 2/23/2009

Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.