What’s The Difference Between A Food Allergy & Sensitivity? 7 Signs You’re Intolerant, Not Allergic

If you always feel kind of ~off~ after eating a particular dish, you might think you're allergic to it — but that isn't necessarily the case. One of the biggest myths about food allergies is that they're just "more extreme" food intolerances, but there are actually major differences between a food allergy and a sensitivity: The two things are actually medically distinct and related to completely different parts of bodily function. It's important to be able to tell them apart, to make sure that you're not accidentally taking the wrong steps to keep yourself healthy. The confusion, allergy organization Allergy UK tells Bustle, "has promoted a growing enterprise for inappropriately trained people to sell many alternative tests purported to diagnose allergies and intolerances." So don't trust what you find on the health food shelf: know the difference.

It's important to note what a food intolerance is and isn't. It is a digestive issue that means your body can't process the food in your system properly, for a variety of reasons: lacking the correct enzymes (as in gluten or lactose intolerance), irritable bowel syndrome, sensitivity to food additives, or stress. It is not a dislike of a food or a tendency to get sick if you eat past-its-use-by-date sushi. The EU Safe Food Council explains, "Food poisoning from eating contaminated food, and food aversion — where someone just doesn’t like a particular food (but will not be ill if they eat it) — are not food hypersensitivities."

So you may be feeling sick because of bad food hygiene, or because you don't really like what was on your plate — but that discomfort should clear up soon, and is avoidable by practicing good food hygiene and avoiding food you're averse to. And of course, the best way to tell if you're intolerant of a certain food or allergic to it is by going to the doctor — and going to the doctor is really the only way you should ascertain if you have what could be a serious allergy. Here are some ways you may be able to tell if you have a food intolerance, rather than an allergy.

1You Don't Experience An Extreme Reaction

WPA Pool/Getty Images Entertainment/Getty Images

One of the major markers of intolerance versus an allergy is the degree of reaction that you experience when you ingest the food in question. If you experience immune system reactions like hives, difficulty breathing, swelling of the body, or anaphylactic shock (the most serious allergic reaction there is), your problem is an allergy. If your problem is more located in the digestive system and produced nausea, vomiting, a bit of discomfort or other mild symptoms, it's probably an intolerance.

"A true food allergy," says the Mayo Clinic, "causes an immune system reaction that affects numerous organs in the body... In some cases, an allergic food reaction can be severe or life-threatening. In contrast, food intolerance symptoms are generally less serious and often limited to digestive problems."

Allergy UK tells Bustle that there are actually two kinds of "true" food allergies. One is an IgE allergy, named for the antibody the body releases to try to and fight the threat. "The immune system usually makes specific IgE antibodies to ‘fight off’ the allergens found in these foods," they say. These are the types most commonly detected by skin-prick or IgE blood tests. "There is another type of food allergy, known as Non-IgE food allergy, which is a true allergic reaction, as it is also caused by the immune system but is not caused by a specific antibody reaction. This occurs most commonly in infants, although it occasionally persists."

2You Can Eat A Small Amount Without Getting Any Problems

Mat Hayward/Getty Images Entertainment/Getty Images

The American Academy of Allergies, Asthma & Immunology writes that often, people with intolerances "can eat small amounts of the food without causing problems." This is because the location of the body's problem with the food differs depending on whether it's an intolerance or an allergy. If you're allergic, your immune system identifies something in the substance you've ingested and immediately marshals defenses against it. If you're simply intolerant, your digestive system can't process it as well as it can a food you're tolerant of, but it's possible that it can handle a miniature amount of the food in question and function relatively normally. That's out of the question with allergies. Even a small amount will set off the immune system's reaction; all food must be prepared without it.

3You Can Reverse The Effects Of Eating The Food

Craig Barritt/Getty Images Entertainment/Getty Images

People with food intolerances can occasionally cope with eating a little of the food and then helping their digestive system deal with the consequences. The Mayo Clinic mentions the example of LactAid, a product that helps people with lactose intolerance process dairy without too many side effects (if they just have to have a slice of cheesecake, for instance).

4Intolerances Are Set Off By Different Foods

Dianne Manson/Getty Images Entertainment/Getty Images

According to research, the categories of food that produce intolerances and allergies are quite dissimilar. The Better Health Channel explains that 90 percent of food allergic reactions are caused by "peanuts, tree nuts, eggs, milk, wheat, sesame, fish, shellfish and soy," while most intolerances center around "dairy products, chocolate, eggs, flavor enhancers, food additives, strawberries, citrus fruit and tomatoes, wines, histamine and other amines." While it's possible to have an allergy to a food item in the second category, it's considered very rare.

6Food Intolerances Can Appear As A Result Of Diet Or Illness

Ethan Miller/Getty Images Entertainment/Getty Images

Allergy UK explains to Bustle that you can "develop" an intolerance because of an illness or a problem with your nutrition, but that's not the case with allergies. "Food intolerance can be caused by different factors, such as lifestyles with erratic food intake and poor nutritional intake or high intakes of refined foods, poor intakes of dietary fibre or high fat diets," they tell Bustle. "Commonly, gastro-intestinal infection can trigger ongoing symptoms such as pain or loose stools after consuming certain foods, for example lactose in milk. The duration of this varies but after excluding the problem foods, usually for some months, they can usually be slowly reintroduced in time."

6The Time Scale Of Reactions Is Different

Tasos Katopodis/Getty Images Entertainment/Getty Images

Compared to allergic reactions, Allergy UK tells Bustle, food intolerance shows up in a more leisurely fashion. "Reactions are usually delayed, occurring several hours and sometimes up to several days after eating the offending food," they say. However, if you've ingested a food you have an allergy to, you know it. Immediately. Whether it's hives, itching, swelling or throat closure, the body's immune system has a very rapid response rate, and leaves you in no doubt as to how serious it thinks the problem is.

7Food Intolerance Symptoms Can Be Longer-Term

Jack Taylor/Getty Images News/Getty Images

If you've been ingesting a food that your gut can't process over the long term, without necessarily realizing that it's causing issues, you can experience symptoms that signify what the body's going through. Food intolerances can spawn both immediate consequences, like diarrhoea and digestive pain, and longer-term issues, like weight loss, fatigue and anemia, as your digestive system struggles to cope with what it's processing and fails to give you enough nutritional support.

If you think you're intolerant or allergic to a particular food, it's always a good idea to get a proper diagnosis from a diagnostician so you can make sure you're getting your proper nutrition — and can stay away from problematic items on the menu.