Symptoms and causes of Lactose Intolerance

Those suffering from Lactose Intolerance often have the following symptoms after eating milk or dairy products:

  • Diarrhea
  • Gas
  • Stomach pain
  • Nausea
  • Vomiting

The causes of the symptoms of Lactose Intolerance

The symptoms are caused by the fact that the body produces too little lactase, which can split the lactose and make it usable for the body.

If the lactose in the small intestine hasn’t been fully split, doctors talk of Lactose Malabsorption. The small intestine cannot absorb the large un-split lactose molecules. The lactose remains in the intestine, where it binds with water - thus triggering diarrhea. If it finally reaches from the large intestine from the small intestine, bacteria attack the lactose. This produces gases such as methane and hydrogen. They explain the flatulence.The larger intestinal filling also expands the intestine and leads to contractions, which can trigger severe pain. In particular, milk contains so much lactose that the consumption of a larger amount causes problems even in people without Lactose Intolerance. The more lactose is absorbed, the more lactase the body needs in order to utilize the milk sugar. Many people suffer from a lactase deficiency when they drink a glass of milk at once - and in this case, the mechanisms described in small intestine and large intestine begin, although there is actually no Lactose Intolerance.

Causes of Lactose Intolerance

Depending on the cause of the Lactose Intolerance, doctors differentiate between different variants:

1.) Primary Lactose Intolerance

By far, the most frequent cause of lactase deficiency is genetic. In many people, the body loses the ability to form the enzyme lactase after the first few years of life. This process usually begins between the ages of 5 and 20 years. Many men and women who are suffering from a primary lactose intolerance still have lactase – just in smaller quantities. This means most people with Lactose Intolerance can tolerate small amounts of milk sugar.

2.) Secondary Lactose Intolerance

Less common are so-called secondary forms of lactase deficiency. These have a different cause. In the case of secondary Lactose Intolerance, affected individuals no longer tolerate milk sugar as a result of a disease such as Celiac Disease or Crohn's Disease. In such cases, Lactose Intolerance is often temporary - if the intestine has the opportunity to regenerate, it also regenerates the enzyme lactase. Frequently, secondary Lactose Intolerance is associated with Fructose Malabsorption.

In some cases, the intestinal flora can also be altered after an antibiotic cure in such a way that those affected temporarily cannot tolerate dairy products.

3.) Congenital Lactose Intolerance

In extremely rare cases, children are born whose metabolism has no lactase at all (alactasia). They suffer from complete Lactose Intolerance which leads to severe diarrhea just a few days after birth. There is a risk of malnutrition and dehydration for these affected infants. They must be fed lactose-free so that they can develop normally.

Please see also:

What is Lactose Intolerance?

Diagnosing Lactose Intolerance

Treatment and therapy for Lactose Intolerance