Food Allergy vs. Food Intolerance: What’s the Difference?

Close up of a woman reading a nutrition label in a grocery store

Food allergies and food intolerance have certain symptoms in common. But the two conditions are very different, particularly in the risk they pose. 

Food allergies involve a reaction from your immune system, whereas food intolerance is a reaction in your digestive system. Consequently, while food intolerance can make you feel uncomfortable, the consequences are primarily limited to your gut. Food allergies, on the other hand, can have wide-ranging effects and can be life-threatening.  

What’s a Food Allergy vs. Food Intolerance?

A food allergy is a condition in which your immune system mistakenly sees a particular food as a dangerous foreign substance and takes action to defend you from it. If, for example, you’re allergic to cow’s milk but you drink some, your body responds by creating antibodies that travel to cells and cause them to release chemicals that ultimately produce an allergic reaction. 

With severe food allergies, a type of reaction called anaphylaxis can occur. It’s a life-threatening condition that requires immediate medical attention. People who have severe food allergies often carry injectable medicine with them that can counteract the reaction until they can get to an emergency room.

Food intolerance occurs if a person is unable to properly digest a particular type of food. For instance, people who are lactose intolerant lack the enzyme needed for the breakdown of lactose. As a result, they experience gas and bloating if they consume it. But this isn’t an allergic reaction — it’s simply their body struggling to deal with food it can’t digest. 

What Are the Signs of Food Allergy vs. Food Intolerance?

Knowing the signs of a food allergy versus intolerance is important, as your response to the two conditions may be very different — most notably a trip to the emergency room for someone who consumes food to which they’re highly allergic. 

Food allergy symptoms

  • Swelling of the throat, tongue, or lips
  • Itching or tingling in the mouth
  • Difficulty breathing
  • Wheezing or coughing
  • Hives
  • Rash 
  • Lightheadedness
  • Nausea 
  • Vomiting

Food intolerance symptoms


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How Do You Find Out if You Have a Food Allergy or a Food Intolerance?

There are two steps to determining if you’re allergic or intolerant to a particular food. The first is simply noting any reaction you have to the food. Food allergies tend to be easier to identify for a few reasons. One is that they come on suddenly. If you’re allergic to shellfish, you’ll likely experience symptoms soon after you start eating it. Also, you don’t have to consume much before an allergic reaction begins. 

The symptoms of food intolerance tend to come on more gradually, and you may have to eat a large amount of the food. Some people only experience symptoms of food intolerance if they eat the food often — the occasional serving of it doesn’t have much if any effect on them. 

If you believe you have a food allergy, your doctor can perform skin testing to check your reaction to food allergens. They can also do blood tests to look for elevated levels of allergy antibodies. 

There aren’t any tests for detecting food intolerance. That diagnosis is based primarily on your reports of what you ate and how you felt afterward. 

What Causes Food Allergies and Food Intolerance?

People can have allergies or intolerance to one food or many foods. 

Food allergy causes

  • Peanuts
  • Milk
  • Tree nuts
  • Shellfish
  • Eggs
  • Wheat
  • Fish
  • Soy

Food intolerance causes

  • Milk, cheese, and other dairy products
  • Gluten
  • Caffeine
  • Chocolate
  • Tomatoes
  • Eggs (egg whites in particular)
  • Strawberries
  • Citrus fruits
  • Wine (especially red wine)
  • Food additives and flavor enhancers like monosodium glutamate (MSG)

Can Food Allergies or Food Intolerances Go Away?

Generally speaking, food allergies and food intolerances are persistent. It’s not unheard of for food sensitivities to change, but if you discover that you have a problem with a particular food, it’s likely that you always will, as these conditions can’t be cured. 

With certain types of food intolerance, taking an enzyme supplement before consuming the food can help. Lactose intolerance is one example. You can take a lactase enzyme supplement before consuming foods containing lactose to minimize or prevent symptoms. 

But the only way to guarantee that a particular food won’t cause you problems is to avoid eating it. That can be challenging, especially since it can be hard to know whether a food is used as an ingredient in a particular recipe. But over time, people with food allergies and intolerances develop a good understanding of where they can expect to find their triggering food(s).  

Talk with Your Doctor About Food Allergy vs. Food Intolerance

There’s a significant difference between food allergy and food intolerance. So, if it seems that your body “isn’t happy” with certain foods, it’s a good idea to determine if you’re allergic to them or have an intolerance issue. Your doctor can help you do this.  

Learn more about food allergies and food intolerance from Baptist Health. If you don’t have a healthcare provider, you can find a provider and location near you at Baptist Health.


Next Steps and Useful Resources

Find a Provider
Start a Virtual Visit
How to Spot a Food Allergy
Milk Has Overtaken Nuts as the Most Severe Food Allergy
Symptoms of Celiac Disease

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