Lactose intolerance is the body’s inability to digest lactose, a sugar found in milk and milk products. Most people with lactose intolerance can tolerate some amount of lactose in their diet.
Lactose intolerance can be confused with an allergy to cow’s milk. Milk allergy is a reaction by the body’s immune system to one or more milk proteins. It can be life threatening – even when just a small amount of milk or milk product is consumed. Milk allergy most commonly appears in the first year of life, while lactose intolerance occurs more often in adulthood.