What should you know about home lactose intolerance test?

Lactose is the natural sugar in milk. Lactose intolerance happens when the small intestine does not make enough lactase to digest it, allowing undigested lactose to reach the colon. This can lead to bloating, abdominal pain, gas or diarrhoea after dairy, although similar symptoms can have other causes.

Some home kits use a breath sample, a blood sample or an elimination-and-reintroduction approach. Read the instructions closely and remember that a result may be affected by recent food choices, digestive conditions, medicines or an incorrectly collected sample. A positive result does not explain every symptom, and a negative result does not rule out another food sensitivity or bowel problem.

Keep a simple diary of dairy foods, portion size, timing and symptoms. Do not remove all dairy for a long period without a plan, because milk and yoghurt can contribute calcium and other nutrients. A clinician or nutrition professional can help you test a measured reduction and choose suitable alternatives.

If symptoms continue, arrange an assessment and take the kit result and food diary with you. Clinical [Food Intolerance Testing](/treatments/diagnostics-and-screening/food-intolerance-testing/) may be considered when the history is unclear. [Nutrition Counselling](/treatments/lifestyle-and-wellness/nutrition-counselling/) can help protect nutrition while identifying triggers.

Seek medical advice for persistent diarrhoea, repeated vomiting, unexplained weight loss, blood in the stool, fever, severe abdominal pain or symptoms that wake you from sleep. Get urgent help for swelling of the lips or tongue, breathing difficulty, faintness or widespread hives after food, because these can suggest an allergic reaction rather than lactose intolerance.

Ask whether your pattern fits lactose intolerance, whether another condition should be considered, and how to reduce dairy without missing key nutrients. You can also ask how to interpret the particular home kit and whether supervised testing is appropriate.