Lactose Intolerance: Symptoms, Causes, Diagnosis, Stages & Treatment

There are three types of lactose intolerance: primary, secondary, and congenital.

1. Primary lactose intolerance is the one of the most common types and occurs when the body produces insufficient lactase enzyme, which is responsible for breaking down lactose in the small intestine.

2. Secondary lactose intolerance occurs due to damage or injury to the small intestine, which may be caused by conditions such as celiac disease, inflammatory bowel disease, or chemotherapy.

3. Congenital lactose intolerance is a rare genetic condition that occurs in infants. It is caused by the absence of the lactase enzyme, leading to an inability to digest lactose.

Some common lactose intolerance symptoms include:

• Abdominal pain and bloating

• Diarrhoea or loose stools

• Gas and flatulence

• Nausea and vomiting

• Dehydration

In addition to the typical symptoms listed above, some people may experience symptoms, such as:

• Cramping and stomach discomfort

• Constipation

• Headaches

• Fatigue

• Muscle weakness

• Skin rash or itching

The severity of the symptoms can vary depending on the amount of lactose taken and the individual's tolerance level. Some people may only experience mild symptoms, while others may experience severe symptoms that can significantly impact their quality of life. It is important to note that the symptoms of lactose intolerance can also be similar to other digestive disorders, so it is essential to get a proper diagnosis to determine the underlying cause of the symptoms.

Lactose intolerance causes the inability of the body to produce sufficient lactase enzyme, which is necessary for the proper digestion of lactose. Lactose is a kind of sugar found in milk and other dairy products. When lactose enters the small intestine, it is broken down into two smaller sugars, glucose, and galactose, by the lactase enzyme. These sugars are then absorbed into the bloodstream and used by the body for energy.

However, when the body does not produce enough lactase enzyme, lactose remains undigested and moves into the large intestine. In the large intestine, bacteria ferment the lactose, causing the production of gases and acids that can lead to the symptoms of lactose intolerance.

There are two main types of lactose intolerance - primary and secondary. Primary lactose intolerance is a genetic condition when the body produces less lactase enzyme than usual. This type of lactose intolerance is more popular in people of African, Asian, Hispanic, and Native American descent.

Secondary lactose intolerance, on the other hand, is caused by an injury or damage to the small intestine, which can reduce the production of lactase enzymes. Some conditions that can cause secondary lactose intolerance include celiac disease, inflammatory bowel disease, and radiation therapy.

While lactose intolerance can be uncomfortable, it is not a severe medical condition. However, if left untreated, it can result in dehydration, malnutrition, and other health problems. Therefore, if you are experiencing symptoms of lactose intolerance, it is crucial to speak with your healthcare provider to get a proper diagnosis and to discuss your treatment options. 

Various factors can increase an individual's risk of developing lactose intolerance. Here are some of the most common risk factors for lactose intolerance:

1. Age: Lactose intolerance is more common in adults than in children. As individuals age, their lactase enzyme production decreases, leading to a higher likelihood of lactose intolerance. In some cases, lactose intolerance may develop during adolescence or adulthood.

2. Ethnicity: Some ethnic groups have a higher prevalence of lactose intolerance. For instance, lactose intolerance is more common among people of Asian, African, Native American, and Hispanic/Latino descent. In contrast, lactose intolerance is less common among people of European descent.

3. Medical Conditions: Certain conditions can cause lactose intolerance or increase the risk of developing it. These include:

   • Celiac disease: This disease is an autoimmune disorder that affects the small intestine. People with celiac disease cannot tolerate gluten, a wheat, barley, and rye protein. Over time, celiac disease can damage the small intestine and decrease the production of lactase enzymes, leading to lactose intolerance.

   • Inflammatory bowel disease (IBD): IBD is a group of chronic inflammatory disorders that affect the digestive tract. People with IBD, including Crohn's disease and ulcerative colitis, may experience damage to the lining of the small intestine, leading to lactose intolerance.

   • Chemotherapy: Some cancer treatments, including chemotherapy, can damage the lining of the small intestine and reduce the production of lactase enzyme, leading to lactose intolerance.

   • Radiation therapy: Radiation therapy to the abdomen can damage the small intestine and decrease the production of lactase enzyme, leading to lactose intolerance.
     

4. Premature birth: Premature infants are at a higher risk of lactose intolerance because they may not have fully developed lactase enzyme production.

5. Gastrointestinal surgery: Some types of gastrointestinal surgery, including bariatric surgery, can cause lactose intolerance by reducing the amount of lactase enzyme-producing cells in the small intestine.

Understanding the risk factors for lactose intolerance is essential for early diagnosis and management of the condition. For example, suppose you are at a higher risk of lactose intolerance due to age, ethnicity, or medical history. In that case, it is essential to be aware of the symptoms and take steps to manage the condition.

Lactose intolerance is a condition that cannot be prevented, but it is possible to reduce the severity of symptoms by making specific dietary and lifestyle changes. The following are some ways to help manage the condition:

1. Limit or avoid dairy products: The most effective way to prevent lactose intolerance is to limit or avoid dairy products. However, it is vital to note that not all dairy products contain the similar amount of lactose. For example, some cheeses and yogurts may be better tolerated than milk or ice cream. Lactose-free or low-lactose dairy products are also available.

2. Alternative sources of calcium: Since dairy products are a significant source of calcium; it is essential to include alternative sources of calcium in the diet to prevent deficiencies. Some non-dairy sources of calcium include leafy green vegetables, almonds, fortified plant-based milks, and canned fish with bones.

3. Probiotics: Probiotics are live bacteria that can improve gut health and reduce the severity of lactose intolerance symptoms. Probiotics can be found in some dairy products, such as yogurt, and other foods like kefir, sauerkraut, miso, and kimchi.

4. Lactase supplements: Lactase supplements are available over the counter and can help break down lactose in the digestive system. These supplements can be taken before consuming dairy products to help reduce symptoms. It is recommended to follow the instructions on the label and speak with a healthcare provider before taking any new supplements.

5. A gradual introduction of dairy products: Some people with lactose intolerance may sometimes tolerate small amounts of lactose over time. Gradually introducing small amounts of dairy into the diet and monitoring symptoms can help determine individual tolerances.

Note that lactose intolerance is not the same as a milk allergy, and avoiding dairy products altogether is unnecessary for everyone with lactose intolerance. In addition, some people may tolerate lactose better if consumed with a meal or in smaller quantities. Listening to your body and working with a healthcare provider or registered dietitian is essential to determine the best approach for managing lactose intolerance.

Diagnosis of lactose intolerance can be challenging since its symptoms are common in many other gastrointestinal conditions. Therefore, to confirm lactose intolerance, a combination of tests is used.

Lactose Tolerance Test

A lactose tolerance test is a common way to diagnose lactose intolerance. During this test, you will be asked to drink lactose liquid. Blood samples are taken regularly over a few hours to measure blood glucose levels. If your blood glucose levels do not increase after drinking the lactose solution, it could mean your body is not digesting lactose.

Hydrogen Breath Test

A hydrogen breath test measures the hydrogen amount in your breath after consuming a lactose solution. When lactose is not digested in the small intestine, it reaches the colon, fermented by the bacteria, producing gases such as hydrogen. If the hydrogen breath test shows high levels of hydrogen in the breath, it indicates that your body is not digesting lactose.

Stool Acidity Test

A stool acidity test is often used to diagnose lactose intolerance in infants and young children. This test measures the acidity of the stool, which increases when bacteria ferment undigested lactose in the colon.

These tests are safe and straightforward and can be performed in a gastroenterologist's office.

Lactose intolerance has different stages of severity.

• Stage 1: Early onset lactose intolerance typically develops during infancy or early childhood due to genetic factors. Infants may have difficulty tolerating lactose in breast milk or formula and experience symptoms such as diarrhoea, vomiting, and failure to thrive.

• Stage 2: Primary lactose intolerance is the most common form and typically develops in adolescence or adulthood. This lactose intolerance is caused by decreased lactase enzyme production and can lead to symptoms such as bloating, gas, and diarrhoea.

• Stage 3: Secondary lactose intolerance can develop due to injury or damage to the small intestine. This can be caused by celiac disease, inflammatory bowel disease, or radiation therapy. Symptoms may include severe abdominal pain, diarrhoea, and weight loss.

• Stage 4: Congenital lactase deficiency is a rare genetic disorder in which an individual is born unable to produce lactase. Symptoms of lactose intolerance typically appear within days of birth and can include severe diarrhoea, vomiting, and dehydration.

The lactose intolerance treatment involves dietary modifications and other measures. Some common treatments include:

• Avoiding or limiting dairy products

• Taking lactase enzyme supplements

• Choosing lactose-free or low-lactose dairy products

• Consuming alternative sources of calcium and other nutrients

• Taking probiotics

The lactose intolerance recovery time varies depending on the severity of the condition. Symptoms may be managed with simple dietary modifications and other measures in mild cases. In severe cases, lactose intolerance treatment may be necessary, and recovery may take longer. After recovery, it is essential to continue to manage the condition through dietary modifications and other measures to prevent a recurrence of symptoms.

1. Can lactose intolerance be cured?
   No, lactose intolerance cannot be cured, but the symptoms can be managed through dietary modifications and other treatments.

2. Is lactose intolerance the same as a milk allergy?
   No, lactose intolerance and milk allergy are two different conditions. Lactose intolerance is the inability to digest lactose, while milk allergy is an immune response to proteins in milk.

3. Can lactose intolerance develop suddenly?
   Yes, lactose intolerance can develop suddenly due to injury, infection, or other medical conditions that damage the small intestine.

4. Can lactose intolerance cause weight gain?
   No, lactose intolerance does not cause weight gain. In fact, avoiding dairy products may help with weight loss.

5. Are there any lactose-free dairy products?
   Yes, lactose-free dairy products, such as milk, cheese, and ice cream, are available. These products are treated with lactase enzymes to break down lactose.

6. Can lactose intolerance lead to nutrient deficiencies?
   Yes, avoiding dairy products can lead to nutrient deficiencies if alternative sources of calcium and other nutrients are not included in the diet.

7. Can lactose intolerance affect mental health?
   Yes, lactose intolerance can affect mental health by causing anxiety, depression, and social isolation due to the limitations it places on the diet.

8. Can lactose intolerance cause skin problems?
   Yes, lactose intolerance can cause skin problems such as eczema, hives, and acne in some cases.

9. Can lactose intolerance be inherited?
   Yes, lactose intolerance can be inherited, particularly in people of African, Asian, or Hispanic descent.

10. Can lactose intolerance cause digestive problems other than those listed as symptoms?
    Yes, lactose intolerance can cause other digestive problems, such as abdominal cramping, constipation, and acid reflux.