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Lactose Tolerance Test

Testing Method:
Blood draw
Test Preparation:
Fasting is required at least 8 hours before testing.
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Not to be confused with the cow's milk allergy test, the Lactose Tolerance Test is designed to determine any lactose intolerance. When a person is lactose intolerant, the body cannot break down lactose (a milk sugar) which can cause abdominal pain, bloating, flatulence, nausea, diarrhea, or skin rashes. This test requires that individuals fast for 8 hours prior to the procedure (i.e. no food or drink besides water). In addition, because of the complexity of this test, the lactose tolerance test takes substantially longer than other Priority Lab options (approximately three hours), so plan accordingly. The technician will first draw a fasting blood sample and immediately administer a 50g dose of lactose via a water solution. Afterwards, blood will be drawn at the 30-minute mark, 60-minute mark, two-hour mark, and three-hour mark. Lactose intolerance reactions at each stage will be reflected in your results.