What should you know about mild lactose intolerance?

Lactose is the natural sugar in milk. The small intestine uses an enzyme called lactase to break it down. When less lactase is available, undigested lactose reaches the colon, where bacteria process it and produce gas and draw in fluid. Symptoms can appear after milk, ice cream, soft cheese or other dairy foods, while tolerance varies between people and between portions. Mild symptoms do not establish the cause on their own; irritable bowel symptoms, infection and other food reactions can feel similar.

Keep a brief food-and-symptom diary and notice whether portion size, meal timing and the type of dairy change your response. Try smaller servings with meals rather than removing every dairy food at once. Lactose-free milk and yoghurt may be easier to tolerate, and some hard cheeses contain less lactose. Avoiding dairy completely without a replacement plan can reduce calcium and vitamin intake, so a nutrition counsellor can help you choose suitable alternatives. Food intolerance testing may be discussed when the pattern remains unclear.

Arrange a medical review if symptoms persist, disturb sleep, lead to unplanned weight loss, or include blood in the stool, repeated vomiting or marked pain. Seek urgent help for swelling of the lips or tongue, breathing difficulty, faintness or widespread hives after food, because those features suggest an allergic emergency rather than simple lactose intolerance.

Ask whether your symptom pattern fits lactose intolerance, whether another digestive problem should be considered, and how to maintain calcium and vitamin intake if you reduce dairy.