Milk allergies, like most food allergies, are relatively rare, and many of those allergies are in small children. Many people who think they are allergic to milk may instead suffer from some degree of lactose intolerance.
Lactose intolerance is caused by an inability to properly digest the natural sugar lactose, which is found in milk and milk products. Symptoms of lactose intolerance include stomach cramping and diarrhea following consumption of dairy products, particularly fluid milk. Very few individuals actually suffer symptoms when consuming normal servings of dairy products along with a meal.
Even these symptoms, however, do not necessarily mean lactose intolerance. While approximately one in four Americans suffers from some degree of lactose intolerance, there are a lot of people who believe they are lactose intolerant but actually are not. Lactose intolerance should be diagnosed properly by a health-care provider.
The good news is even people who suffer from lactose intolerance don't have to avoid dairy products entirely. There are many lactose-reduced and lactose-free milks and other products on the market, as well as tablets or drops that may be taken with dairy products to aid lactose digestion. Research has shown that most people with lactose intolerance can consume comfortably up to two cups of regular fluid milk each day, starting with a small amount with a meal first, and building up over a period of weeks.