Warning signs you may be lactose intolerant

Lactose intolerance occurs in people who lack the enzyme needed to break down lactose, the sugar in milk. It causes indigestion when you eat dairy products. Here are common signs of lactose intolerance .

Mouth ulcers

Dairy products such as milk, cheese, and yogurt have all been linked to mouth ulcers. Some experts believe that the protein in cow's milk may trigger mouth ulcers in some individuals due to an adverse immune response.

If you frequently suffer from mouth ulcers, consider cutting back on dairy, especially animal products. Instead, try alternatives like soy milk, oat milk, and vegan cheeses to see if these changes help reduce mouth inflammation.

Swelling

Milk allergy or lactose intolerance can cause reactions beyond the digestive system, affecting the skin, lungs, and other organs. Common symptoms include:

1. Rash
2. Hives
3. Swelling (especially around the lips and face)
4. Wheeze
5. Tight throat
6. Difficulty swallowing
7. In infants, bloody stools can also occur.

Severe reactions, such as swelling of the throat and difficulty breathing, may indicate anaphylaxis, a life-threatening allergic reaction. Symptoms usually appear within minutes of consuming milk but may be delayed for hours. If anaphylaxis occurs, immediate action is needed—inject epinephrine (if available) and seek emergency medical attention. If epinephrine is not available, go to the nearest emergency room as soon as possible.

Diarrhea or constipation

Lactose intolerance occurs when the body has difficulty digesting lactose, the natural sugar found in milk, leading to digestive problems such as diarrhea after consuming milk. While not harmful, it can cause significant discomfort.

Interestingly, lactose intolerance does not always cause diarrhea. In some cases, especially for people whose gut bacteria produce methane instead of hydrogen, constipation can be the main symptom. Research shows that methane slows down bowel movements, leading to constipation in about a third of people with lactose intolerance.

Flatulence

Gas is a common symptom of lactose intolerance in both children and adults. It occurs when the body lacks lactase, an enzyme needed to break down lactose, the natural sugar found in dairy products.

If not digested properly, undigested lactose travels to the colon, where gut bacteria ferment it, leading to bloating and discomfort.

Headache and fatigue

In addition to digestive discomfort, lactose intolerance can cause symptoms including back pain, headaches, fatigue, difficulty concentrating, and general tiredness. Some patients also report sleep disturbances, dizziness, and a general feeling of malaise.

These less common symptoms may stem from the body's inability to process lactose properly, causing an inflammatory or metabolic response in sensitive individuals.

Micah Soto

Update 03 February 2025