Wikipedia:VideoWiki/Lactose intolerance terminology

Introduction
Lactose intolerance primarily refers to a syndrome having one or more symptoms upon the consumption of food substances containing lactose. Individuals may be lactose intolerant to varying degrees, depending on the severity of these symptoms.

Lactose malabsorption
"Lactose malabsorption" refers to the physiological concomitant of lactase deficiency. In other words, the body does not have sufficient lactase capacity to digest the amount of lactose ingested.

Hypolactasia
Hypolactasia, lactase deficiency, is distinguished from alactasia, total lack of lactase, a rare congenital defect.

Is not an allergy
Lactose intolerance is not an allergy, because it is not an immune response, but rather a sensitivity to dairy caused by lactase deficiency. Milk allergy, occurring in only 4% of the population, is a separate condition, with distinct symptoms, that occur when the presence of milk proteins trigger an immune reaction.