The Lactose Intolerance Test is a medical procedure used to determine if a person has difficulty digesting lactose, a sugar found in milk and dairy products. During the test, the individual consumes a drink containing lactose, and then their blood sugar levels are measured over a few hours. If the blood sugar levels do not rise significantly, it indicates that the body is not properly breaking down lactose. Another method is the Hydrogen Breath Test, where the patient breathes into a device after consuming lactose. Increased levels of hydrogen in the breath suggest that lactose is not being digested, leading to fermentation in the gut. Both tests help diagnose lactose intolerance.