Lactose intolerance - Symptoms 

Symptoms of lactose intolerance 

The symptoms of lactose intolerance will occur after consuming food or drink that contains lactose, such as dairy products.

The main symptoms include:

  • flatulence (wind)
  • diarrhoea three or more times a day
  • bloated stomach
  • stomach pains
  • stomach rumbling
  • feeling sick
  • stomach cramps

The severity of your symptoms and when you begin to experience them will depend on the amount of lactose that you have consumed.

The amount of lactose that it takes to cause your symptoms will vary from person to person. For example, some people may still be able to drink a small glass of milk without triggering any symptoms, while others may not even be able to have milk in their tea.

Conditions that cause similar symptoms

The symptoms of lactose intolerance can be similar to those of other conditions, such as irritable bowel syndrome (IBS) or milk protein intolerance. IBS is a chronic (long-term) disorder that affects the digestive system.

Milk protein intolerance is an adverse reaction to the protein in milk from cows, but it does not involve the immune system (and so is not the same as milk allergy). Due to the similarities, these three conditions can sometimes be confused.

This is why it is always important to get a medical diagnosis if you think that you or your child may have lactose intolerance.

Read more about diagnosing lactose intolerance.

Page last reviewed: 17/05/2012

Next review due: 17/05/2014


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The 3 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Lily clucky said on 14 March 2014

Melly41, there is a large range of Lactofree products in most supermarkets with products including milk, cheese, cream custard etc. vitalite is also dairy free and can be used to bake with.
There are free from ranges which also clearly mark what does not contain dairy.
I found this very hard to deal with at first but this was over 15 years ago, there are so many good dairy and/or Lactofree products available that with a few changes you will barely notice. It is worth researching lactose content in different types of cheese as you may be able to reintroduce these later on once your condition is under control.
That being said there is medication that you can take if you do get a flare up. Xxx

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Melly41 said on 09 January 2014

Hi. I've had a diagnosis from my gp today. My results have come back saying I'm lactose intolerance. I know nothing about this. I would really appreciate any advice in what I can and cannot eat. It's so hard as I'm not aloud dairy products. Can someone plz advice me. Thank-you

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rach_o said on 12 February 2013

Recently I have started experiencing headaches at the left hand side at the back of my head after consuming lactose. I just wondered if anyone else has anything similar? I've always been lactose intolerant and never experienced this before.

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Is it a food allergy or intolerance?

Around 2% of people in the UK have a food allergy, but many more have a food intolerance