Lactose intolerance - Symptoms 

Symptoms of lactose intolerance 

The symptoms of lactose intolerance will usually occur within a few hours of consuming food or drink that contains lactose, such as dairy products.

The main symptoms include:

  • flatulence (wind)
  • diarrhoea
  • bloated stomach
  • stomach cramps and pains
  • stomach rumbling
  • feeling sick

The severity of your symptoms and exactly 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 or coffee.

Seeking medical advice

The symptoms of lactose intolerance can be similar to those of other conditions, so it's important to see a GP for a medical diagnosis if you think you or your child may be lactose intolerant.

For example, the symptoms above can also be caused by:

  • irritable bowel syndrome (IBS) – a long-term disorder that affects the digestive system
  • milk protein intolerance – an adverse reaction to the protein in milk from cows (not the same as a milk allergy)  

Read more about diagnosing lactose intolerance.

Page last reviewed: 28/04/2014

Next review due: 28/04/2016


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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