Cow milk being put into a glass cup

Types of lactose intolerance


A patient goes to the doctor with pain, vomiting, swelling, and discomfort complaints. The doctor will ask about the last meal. The patient says that he had ice cream, milk, or cheese. So there it is—a very typical case of lactose intolerance. 

The doctor sends the patient for a lactose tolerance test. If it comes out positive. The patient is lactose intolerant. They cannot consume dairy products because of this intolerance in their bodies. 

So what put s someone at risk of being intolerant to lactose? What are the different types of lactose that can occur? Let’s dive deeper into this common digestive problem..

What puts you at risk?

We observed both the children and adults having the issue in various clinical settings. This digestive problem can occur in both adults and children as well and sees no partiality in gender. However there are certain races that seem more favourable to acquire this digestive problem. So, what factors can put you at risk? The answer lies below, 

  1. Increasing age can decrease the lactase in your body. 
  2. You are at risk if you are a descendant of Asian, American, or Hispanic races.
  3. Infants who are born prematurely are at risk. 
  4. People who have received cancer treatment.

If you have any of the aforementioned conditions, you may develop the disease. 

three cows

Classification of lactose intolerance 

We have found specific different presentations of lactose intolerance. Some have it by birth; others get it in adulthood. From these differences, we have classified it into different types. Primary, Secondary as well as more genetic types like Congenial and developmental and familial.

There are four main types of lactose intolerance. We classify them based on causes and age of presentation. 

These four types are,

  1. Primary
  2. Secondary
  3. Congenital or developmental
  4. Familial

We are going to do a quick study of them in this article, one by one. 

Primary lactose intolerance

There is a strong genetic association with primary lactase deficiency. This means that it is likely inherited, increasing your likelihood of acquiring this deficiency because of your parents or because of your genetics or race. In addition, it is the most common presenting type. It can develop between infancy and early adulthood. We are usually born with enough lactase. However, it decreases over time, and you become lactose intolerant. 

This type is common in some races. For example, Hispanic, Asian and African races have a unique intolerance among them to develop this type.

Secondary lactose intolerance

We call it secondary because some underlying pathology causes it. The diseases are prevalent, like inflammatory bowel and coeliac disease. Other factors that cause secondary lactase deficiency is,

  1. Antibiotics
  2. Cancer treatment
  3. Crohn’s disease
  4. Ulcerative colitis 
  5. Ischemic bowel disease, etc. 

All these conditions are deemed to be long-term, and all of them involve themselves on some part within the small intestine. These issues can be short-term. There are postive news to people experiencing any of these symptoms as this temporary condition might subside after receiving proper treatment. 

cows on mud

Congenital or developmental lactose intolerance

Congenital or developmental deficiency is present right from birth. It is a rare condition that does not affect most children and is likely inherited from the genes of one or both of their parents. This genetic inheritance results in a complete absence of lactase.

It can be severely life-threatening because the child cannot digest breast milk which is crucial for their growth and development. However this condition can be treated by using lactose-free formula milk.

Familial lactose intolerance

Familial deficiency of lactase has similarities to the congenital one. Once again the condition is due to the inheritance of faulty genes from the parents. This time the actual problem lies not with enzyme production but with its function. This remains to be the sole difference between congenital and familial lactase deficiency.

Other Symptoms

There are many symptoms of lactose intolerance. The first symptom is watery diarrhea. It can be a sign of malnutrition or an infection of the small intestine. A lactose-free diet will alleviate the symptoms. The next symptom is a rise in gas. Often, the symptoms go away on their own once the patient reduces their lactose intake.

There are some common symptoms of lactose intolerance, such as gas and bloating, that can be linked to race. Most people who are intolerant to dairy products are of African or Asian descent, and the disorder can be passed down through generations. However, it is unclear whether lactose intolerance is a racial trait or a symptom of other conditions.

How Race is involved

It is believed that about thirty to fifty million people in the United States are lactose intolerant, with nearly 80 percent of African Americans, Native Americans, and Asians affected. It is rarer among people of Northern European heritage. However, it is important to note that people with intolerant levels of lactose are likely to drink milk for the rest of their lives. In addition, many people with intolerance are unaware of it until it is too late.

The percentage of lactase intolerance varies based on race. Most Europeans have a low percentage, while Hispanics and Afro-Americans have the highest prevalence. Most people produce plenty of lactase in their early life, but those of northern European descent tend to keep it until adulthood. The researchers analyzed data on the prevalence of lactose intolerance in 39 ethnic groups. They also studied 270 indigenous African and Eurasian populations.

If you’ve been diagnosed with osteoporosis, it might seem that there is only one race that causes it. However, this race concept is not as simple as it sounds. It can be both genetic and societal. People are lumped together based on appearance and assume that the same biological or cultural characteristics apply to all of them. While race is an imperfect description, socially defined races can still be useful.

While dairy products are the most common source of calcium, individuals with lactose intolerance might assume they have a higher risk of osteoporosis. However, research has produced conflicting results. Some studies have suggested that people with lactose intolerance are at increased risk of low bone density, while others found no connection between lactose intolerance and osteoporosis. Therefore, individuals with lactose intolerance should follow the same basic strategies as those with normal bone density. However, they should pay particular attention to calcium intake.


To sum up, your patient can present with any of these types. A trained physician can diagnose all these through the lactose tolerance test. However, the presentation time will differentiate these types in the clinical setting.