Is Lactose Intolerance an Allergy?

Imagine you’ve just purchased a fresh box of Oreos, and poured yourself a tall glass of rich, delicious milk. The snack is epic, but two hours later, your stomach starts rumbling, and you feel the sudden urge to rush to the bathroom. A few hours later, once you’ve been depleted of most of your bodily fluids, you begin to wonder whether three glasses of milk was too much.

The other worry, of course, is that you are starting to show signs of lactose intolerance. It is believed that roughly 50 million Americans alone suffer from this condition, leading many to wonder what it really means. First things first, is lactose intolerance an allergy?


Short answer:¬†No, it’s not an allergy, it’s a deficiency in a certain type of enzyme, although many of the symptoms do resemble that of a food allergy.

What is Lactose Intolerance?

Most people immediately assume that lactose intolerance is an allergy, given the violent gastrointestinal reactions that it can cause. However, there is another allergy related to milk, with a rather obvious name… milk allergy. You see, lactose intolerance is caused by the lack of a particular enzyme in the body, called lactase. The sole purpose of lactase is to break down lactose, which is the type of sugar found in milk and the majority of dairy product.

When you have the enzyme, lactose is broken down into glucose and galactose, which are naturally absorbed by the lining of the intestines. However, without the enzyme to break it down, the lactose cannot be processed and digested, and moves into the colon. Here, it interacts with the bacteria present, causing you to feel the traditional symptoms of lactose intolerance – stomach pain, nausea, diarrhea, cramping and bloating. This can happen quickly, as soon as 30 minutes after eating dairy, or can be delayed by more than two hours. Either way, when it hits you, it will probably be unpleasant.

Milk allergy, on the other hand, is an actual allergy, not a deficiency. Basically, someone with a milk allergy is reacting to the specific proteins found in the milk. This is how other allergic reactions also occur – false stimulations of the immune system that result in allergy symptoms. Most people with milk allergy are only sensitive to cow’s milk, and these allergies often appear in young children, and disappear by the age of 5 or so. Some adults remain sensitive and allergic to milk, but those numbers are quite small.

The symptoms of a milk allergy are quite similar to lactose intolerance, but there are a few extra that resemble more traditional allergic reactions. Along with stomach upset, diarrhea, cramping, bloating and nausea, you may also see skin rashes, difficulty breathing and swelling in certain parts of the body, such as the hands and throat. Fortunately, most early allergic testing can show a milk allergy, so you can keep your child safe from these symptoms.

Again, lactose intolerance is far more common, and is definitely the bigger culprit when it comes to keeping adults off the dairy. If you happen to be someone suffering from lactose intolerance, or if you suspect that you might be developing it, you should know a bit more about the causes and manifestations so you can plan accordingly!

The Variety of Lactose Intolerance

There are three main types of lactose intolerance, all of which cause a lactase deficiency in your body for different reasons. Primary lactose intolerance is by far the most common, and is characterized by a sharp decline in lactase production. This can happen in young adulthood, as children move more from dairy-based products to other foods, but primary lactose intolerance can also manifest at a much later time. This can often decline over time, leaving you extremely sensitive to lactose-containing foods by the time you reach adulthood.


Secondary lactose intolerance is caused by some other illness, infection, or surgery to the small intestine, which compromises your body’s ability to create lactase and digest dairy products. Some of these conditions include Crohn’s disease and Celiac disease, which are commonly seen in conjunction with lactose intolerance, making their dietary choices even more limited! If you are able to mitigate the symptoms of the infection, condition, or illness, you can often live a relatively normal life with secondary lactose intolerance. Certain cancer treatments have also been connected to an increased likelihood of secondary lactose intolerance.

The final variety is congenital lactose intolerance, which is definitely the most rare, but can cause a child to be born without any lactase production in its body. If infants are born premature, they may also lack the lactase-developing skills, and will have some form of congenital lactose intolerance as they age.

Clearly, if you have a milk form of lactose intolerance, the occasional Oreo dip party isn’t completely out of the question, but you need to be careful about how often you take that chance, as you could be doing permanent damage to your small intestine or colon. Be smart and speak with your doctor about alternative options that don’t contain lactose. After all, what kind of life is a life without cheese!


  1. Healthy Living With Lactose Intolerance – WebMD
  2. Diseases and Conditions Lactose intolerance – Mayo Clinic
  3. Lactose Intolerance – CiteSeerX
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About the Author:

John Staughton is a traveling writer, editor, publisher and photographer who earned his English and Integrative Biology degrees from the University of Illinois. He is the co-founder of a literary journal, Sheriff Nottingham, and the Content Director for Stain’d Arts, an arts nonprofit based in Denver. On a perpetual journey towards the idea of home, he uses words to educate, inspire, uplift and evolve.

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