Lactose Intolerance: Symptoms, Causes and Treatment

Lactose intolerance is caused by the inability to digest lactose after infancy or adulthood, which results in abdominal pain and diarrhea. Lactase enzyme is required for digesting lactose. This condition can be found in a number of people, who are unable to consume milk or dairy products because their bodies cannot break down lactose.

Lactose intolerance is not a disease itself but it can be an indication of several diseases like celiac disease, Crohn’s disease, and irritable bowel syndrome.

Lactose intolerance can lead to symptoms such as abdominal pain, diarrhea, and gas. In some cases, it can cause more serious problems such as cramps and dehydration.

Lactose intolerance can be diagnosed with a lactose tolerance test, which involves drinking several glasses of milk and measuring the amount of lactase in your digestive tract after 3 hours.

What is Lactose?

Lactose is the primary carbohydrate found in milk and dairy products that provides the essential nutrients for infants, such as calcium, protein, riboflavin, and phosphorus.

Lactose is made up of two molecules, the D-galactose and the D-glucose. Lactase deficiency can be congenital or acquired through age, disease, or injury.

What is Lactose Intolerance?

Lactose intolerance is a digestive condition that affects the body’s ability to digest lactose, which is found in dairy products like milk and cheese. It is most common in people of East Asian descent. Lactose intolerance can be caused by genetics or by an infection with the bacteria “Helicobacter pylori”.

Lactase enzymes are needed for breaking down lactose into two simple sugars called glucose and galactose before it is absorbed into the bloodstream for use as energy or stored for later use. The enzyme lactase helps the cells in your small intestine break down lactose into these two simple sugars.

When you have low levels of this enzyme or your body doesn’t produce enough of it, you might not be able to break down all the lactose you eat. This can cause symptoms like gas, bloating, diarrhea or cramps since the lactose will pass through your digestive tract without being broken down by the lactase enzyme.


Lactose intolerance is a common condition that affects more than 75% of the world’s population. It causes digestive problems and gas in people who are lactose intolerant. For those who have symptoms, it can be difficult to tell if they’re lactose intolerant or just have a sensitive stomach.

A person with lactose intolerance may experience symptoms like gas, bloating, cramps and diarrhea after eating dairy products like milk, ice cream or cheese. These symptoms can vary depending on what kind of dairy product it is and what kind of food it was eaten with.

Symptoms of Lactose Intolerance:

  • Gas
  • Vomiting
  • Diarrhea
  • Bloating
  • Nausea
  • Bloating
  • Abdominal Cramps

Some people also experience an urgent need to go to the toilet, lower belly pain, and constipation.

Lactose intolerance is caused by a deficiency or change in the structure of the lactase gene. This condition can be inherited or acquired through an infection or injury to the gut wall. There are different degrees of severity depending on how severe the symptoms are and how long they last.


Lactose intolerance is caused by an inability to digest lactose, a sugar found in milk and dairy products. Lactose intolerance can be caused by various factors including genetics, environment and diet.

Lactase enzyme deficiency is the most common cause of lactose intolerance. If you have this condition, your body cannot break down lactose and it can lead to digestive problems such as cramps, diarrhea, pain in the abdomen or bloating.

Lactase enzyme deficiency is caused by rare mutations in one of two genes – MCM3 or STM8. It can also be caused by environmental factors such as radiation exposure or certain medications like antibiotics that kill the bacteria in your gut that produce lactase enzymes.


Lactose intolerance is also called lactase deficiency or hypolactasia. It is one of the most common food intolerances in humans.

There are several symptoms associated with both types of lactose intolerance and some people may have more than one symptom from each type of intolerance.

Lactose intolerance can be divided into four types:

Primary Lactose Intolerance

Primary lactose intolerance is a genetic disorder that affects the way the body digests milk sugars, making it difficult to digest milk. In primary lactose intolerance, lactase production falls off sharply by adulthood. It is caused by the body not producing enough of the enzyme lactase that breaks down lactose into glucose and galactose.

Primary lactose intolerance is more common in people who have a history of cow’s milk allergy or celiac disease. It can also be caused by other conditions such as cystic fibrosis and inflammatory bowel disease.

Primary lactose intolerance can be difficult to diagnose because it can cause symptoms that are similar to other conditions such as irritable bowel syndrome, chronic fatigue syndrome, or gastroesophageal reflux disease (GERD).

Secondary Lactose Intolerance

Secondary lactose intolerance is a condition in which the body cannot break down lactose, a sugar found in milk, into lactic acid. Secondary lactase deficiency is caused by an injury or illness that interrupts the production of lactase, an enzyme needed to break down milk sugars.

The most common cause of secondary lactose intolerance is an intestinal bacterial overgrowth. This can be caused by antibiotic use or other medications that inhibit the growth of bacteria.

Secondary lactose intolerance is the condition in which a person has a lactose-intolerance but is not lactose intolerant.

Secondary lactose intolerance occurs in people who have been previously diagnosed with primary lactose intolerance and are managing their symptoms without the need of treatment.

The symptoms of secondary lactose may vary but some of the most common ones include bloating, cramps, diarrhea, gas, nausea, and vomiting.

Congenital Lactose Intolerance

Congenital lactose intolerance is a genetic disorder. It is the inability to digest lactose, the sugar found in dairy products. It occurs when a person’s body does not produce enough of one of the enzymes needed to digest lactose which leads to gastrointestinal symptoms such as bloating, cramps and diarrhea.

Congenital lactose intolerance affects about 1 in 200 people worldwide. It can be detected in infants by using a breath test. It usually develops within the first month of life and most people are diagnosed at around four years old.

The condition is not life-threatening but it can cause severe gastrointestinal issues that affect quality of life for children with congenital lactose intolerance.

Developmental Lactose Intolerance

Developmental lactose intolerance is a condition that occurs when the body’s ability to break down lactose, a sugar found in milk, declines.

Developmental lactose intolerance (DLI) is a condition that occurs when an infant’s body cannot properly break down lactose, a sugar found in milk. It typically only affects premature babies and causes symptoms such as digestive distress.

This condition affects people of all ages from childhood to adulthood. It can cause severe abdominal pain, cramps, diarrhea and bloating. People with this condition typically have to avoid all dairy products because they cannot digest them properly.

Risk factors

Lactose intolerance is a condition in which the body cannot properly digest lactose, the sugar found in milk. It is most commonly associated with dairy products and can be very dangerous if left untreated.

Lactase deficiency is prevalent in some ethnic groups including African Americans, Native Americans and Hispanics/Latinos due to genetic differences in their genes which cause them not to produce lactase efficiently.

Some people may have an increased risk of lactose intolerance. Risk factors to look out for include having the following:

  • Asian or African heritage
  • Medical history of digestive problems
  • Relatives who are lactose intolerant


There are many tests for lactose intolerance, some of which you can do at home and some that you have to get from your doctor.

One way to know if you are lactose intolerant is to do a lactose tolerance test. This test requires that you drink a cup of milk, then wait 15 minutes and see if there are symptoms such as bloating or cramping. The test may also require that you have a stool sample done at the end of the 15 minutes.

If you are lactose intolerant and want to know if you have the condition, there are some simple tests that can be done at home. You can also use these tests to find out what your tolerance for lactose is:

Lactose Tolerance Test:

The Lactose Tolerance Test is a simple test that can determine if a person has lactase deficiency or lactase persistence.

If you are lactose intolerant, blood sugar levels will not be affected by the ingestion of lactose. This is because your body cannot break down lactose into its component sugars in your digestive tract, so it passes through undigested and unfed upon elimination.

Genetic Test:

A genetic test for lactose intolerance can help you determine if you have this condition or not. A genetic test is a blood test that analyzes your DNA to identify the presence of genes related to lactase production but people with secondary lactose intolerance may receive a false negative.

Stool Acidity Test:

The stool test is a simple and inexpensive way to determine whether or not you have lactose intolerance. If your stools are more alkaline after consuming dairy products, it means that you are intolerant of lactose and should avoid all types of dairy products.

Hydrogen Breath Test:

The hydrogen breath test is a useful tool for people with lactose intolerance who experience symptoms such as diarrhea and abdominal pain. The hydrogen breath test can help to determine how much lactase enzyme the individual has in their digestive system. If there is an insufficient amount of lactase enzyme present, then the individual will not be able to break down the sugars in milk and other dairy products.

Lactose intolerance can be tested for by taking a hydrogen breath test that measures hydrogen levels in the exhaled air after consuming milk or other dairy products.


Lactose intolerance is not a disease but it can be treated with dietary changes.

Lactose intolerance is usually treated with lactase enzyme supplements or medications. Lactase enzymes are available over-the-counter or by prescription if symptoms persist.

Lactase tablets are available over the counter and are typically taken on an empty stomach before meals that contain milk products. Lactase drops are available by prescription only and should be used under medical supervision to avoid side effects.

Lactose intolerance can be common among people of Asian descent since they are less likely to have the gene for lactase production than other ethnicities.


Lactose intolerance is a condition in which the body cannot digest lactose, which is a sugar found in dairy products like milk, yogurt, and cheese. It can be caused by genetic mutations, aging, or even after taking antibiotics.

This condition can be treated with medications or dietary changes. It also has risk factors such as ethnicity, diet and age.

Lactose intolerance is a condition that many people are finding themselves in, and there are many ways to adjust your diet to avoid or limit lactose. These strategies include buying lactose-free foods and adjusting your diet accordingly.