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VMA Test |
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VMA Test - VMA Test Definition, Reasons for VMA Test and Results in VMA Test
VMA Test Definition
VMA lab test stands for “Vanillylmandelic acid” and is an end-stage metabolite (intermediates or products of metabolism), adrenalin, and norepinephrine (hormones and neurotransmitter). VMA is generally found in human urine, along with other hormones released by the adrenalin glands in the body to fight stress. It is observed that in patients with tumors that secrete catecholamines the levels of urinary VMA are higher than normal. The VMA test is basically used to detect neuroblastomas in children that have abdominal mass or other symptoms that are associated with the disease. The VMA test is carried out in conjunction with the homovanillic acid test to diagnose neuroblastomas, to monitor the effectiveness of the treatment and also to check for the recurrence of neuroblastomas. A urine creatinine is almost always done, especially with random urine testing, and tests results are usually reported as ratios of VMA-to-creatinine and HVA-to-creatinine. The reason being that creatinine is a substance that is excreted in the urine at a relatively constant rate; and this serves as a comparison to the rate of VMA and HVA excretion.
Reason for VMA Test
VMA lab tests are done when the following signs and symptoms show up in a patient. The presence of any unusual and hard lump in the abdomen, especially near the belly is a symptom. Also the lack of appetite or abdominal pain is a sign to check for neuroblastomas. At times any tumors in the neck which cause swelling and make it hard to swallow or breathe are tell tale signs. Also tumors that press on nerves by the spine may affect a child’s ability to walk. If the tumor spreads to the bones, it may cause pain in the bones, and also may affect the production of blood cells if it spreads to the bone marrow. Fatigue, pallor, and bleeding are also a direct result of tumors in the bone marrow. Bruising around the eyes, drooping eyelids, purple spots on the skin, bladder and bowel dysfunction along with muscle spasms are also noticed in neuroblastoma patients.
Results in VMA Test
There are a lot of false positive results with the test, the reason being that VMA lab tests are sensitive to many other outside influences. If a person has more than normal amount of VMA in his urine, further investigation is necessary to determine its cause. Amount of VMA produces does not have any direct relation to the size of the tumor, as this is mostly a physical characteristic of tumor tissue. Finally a doctor must always be consulted while testing for VMA, or before discontinuing any medication.
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