Explanation
No. Lactose intolerance and milk allergy are different conditions. Lactose intolerance concerns the digestion of lactose, a sugar in milk. Milk allergy involves an immune response to one or more milk proteins.
NIDDK explains that insufficient lactase, the enzyme that breaks down lactose, allows undigested lactose to reach the colon, where it can cause digestive symptoms. The NHS independently identifies low lactase levels as the most common cause and distinguishes food intolerance from food allergy.
The distinction matters because an allergic reaction to milk can be life threatening, whereas lactose intolerance does not operate through that allergic mechanism. These definitions explain the conditions; they do not establish the cause of an individual's symptoms.
Key takeaway
Milk sugar and milk proteins are different triggers. Lactose intolerance and milk allergy are not interchangeable diagnoses.