How Do I Know If I Have Lactose Intolerance?
Last Updated: 12th January 2023 · Written by Donna Mastriani
Between 30 and 50 million adults have Lactose Intolerance making it quite common. The question is, are you lactose intolerant?
Several different symptoms come with a lactose intolerance, and they usually occur within a few hours of consumption. Below are a few symptoms that may indicate an issue if they coincide with eating products that contain lactose.
Diarrhoea
It makes sense that consuming foods you’re intolerant to would disrupt your digestive system and lactose can have a real impact on your bathroom trips. Diarrhoea after lactose is an indicator of an issue and can lead to dehydration and electrolyte imbalance.
Stomach Cramps and Pains
As well as diarrhoea, people with lactose intolerance will often experience extreme stomach cramps. The gases produced by the stomach fermentation process cause this pain. The pain and bloating experience is not related to the amount of lactose imbibed, but the level of intolerance the individual has.

Constipation
If you’re passing infrequent, hard stools or are having to strain excessively, you are likely experiencing constipation. Bacteria ferment the undigested lactose in the stomach, which produces methane gas and this gas is thought to slow down the movement of food through the gut. Constipation is less likely than diarrhoea but is still a potential symptom.
Other potential symptoms
Other symptoms that have possible ties to lactose intolerance include:
- Extreme Fatigue
- Headaches
- Brain Fog
- Eczema
- Joint Pain
Though they have not been proven as established symptoms, they have been reported frequently in case studies.
Other intolerances or allergies cause all of the above symptoms. To establish what might be causing the above symptoms for you, you should take an intolerance test.
