Milk and lactose intolerance

Lactose is a natural sugar in milk. When the body does not digest enough lactose, it can lead to bloating, abdominal pain, gas or diarrhoea after dairy. These symptoms may begin later and are usually limited to the digestive system. Read more about [Lactose Intolerance](/conditions/lactose-intolerance/).

Milk allergy involves the immune system reacting to milk proteins. It may cause hives, swelling, vomiting, coughing, wheezing or throat symptoms, sometimes soon after exposure. A person can have lactose intolerance without milk allergy, or have milk allergy while tolerating some lactose-free products poorly because the proteins remain.

Keep a food and symptom diary, noting the type and amount of dairy and the timing of symptoms. A clinician may recommend a structured reduction and reintroduction plan or [Food Intolerance Testing](/treatments/diagnostics-and-screening/food-intolerance-testing/). Avoid removing all dairy for a long period without advice, because calcium, vitamin D, protein and energy may need replacement.

Some people tolerate small portions, yoghurt or hard cheese better than a glass of milk, but responses vary. Lactase products or lactose-free alternatives may help selected people with lactose intolerance; ask a pharmacist or clinician how to use them. [Nutrition Counselling](/treatments/lifestyle-and-wellness/nutrition-counselling/) can help keep meals balanced.

Arrange medical review for persistent diarrhoea, weight loss, blood in stool, night-time symptoms, repeated vomiting or pain that is severe or worsening. Seek emergency help for breathing difficulty, throat swelling, fainting or widespread hives after dairy, because these signs fit a possible severe allergy rather than simple lactose intolerance.

Ask whether your pattern suggests lactose intolerance, milk allergy or another digestive condition; whether testing is useful; which foods to limit; and how to replace nutrients if dairy is reduced.