Your stomach hurts, and then you notice a red rash on your arms. Was it the banana you ate for breakfast, the PB&J you had for lunch, or the bite of shrimp you took off your partner’s dinner plate last night?

Living with food sensitivities can be frustrating. But with a little effort and the help of a health care professional, you can identify your trigger foods, receive treatment if needed, and start enjoying your meals again.

Do You Have a Food Allergy or a Food Sensitivity?

Knowing whether you have a food allergy or food sensitivity is important because food allergies can be life-threatening. Although some of their symptoms are similar, food allergies and sensitivities affect the body differently.

Food Allergy

According to the American Academy of Allergy, Asthma, and Immunology (AAAAI), a food allergy occurs when the immune system overreacts to even a tiny amount of a particular food. After mistakenly thinking a protein in that specific food is a threat to the body, the immune system sets off an immune response to protect you. Common allergy-trigger foods include shellfish, dairy products, peanuts, tree nuts, eggs, wheat, and soy.

Food allergy symptoms may include the following:

• Rash (hives) and itchy skin
• A stuffy or itchy nose
• Swollen eyes or lips
• Sneezing, coughing, wheezing, or shortness of breath
• Diarrhea, stomach cramps, abdominal pain, or vomiting

Food allergies can cause anaphylaxis, an allergic reaction that requires immediate medical attention. Anaphylaxis occurs when the immune response leads to multiple severe symptoms and may cause low blood pressure.

Food Sensitivity

A food sensitivity, or food intolerance, can lead to some of the same symptoms as a food allergy, but they’re generally less severe and not life-threatening. Food sensitivity symptoms may include:

• Stomach pain
• Bloating
• Joint pain
• Rashes
• Tiredness
• Migraine

Gluten intolerance is a common food sensitivity. Gluten can be found in pasta, cereals, baked goods, sauces, and anything containing wheat flour. Gluten sensitivity is not the same as celiac disease, which is an autoimmune disorder.

Lactose intolerance is another common food sensitivity. People who are lactose intolerant aren’t allergic to lactose, a sugar found in milk and dairy products. Rather, they have adverse reactions like bloating and diarrhea because they lack the enzymes needed to break it down.

If you think you have a food sensitivity or allergy, talk to your doctor. They may refer you to an allergist or gastroenterologist.

Here are four facts about food sensitivity tests.

1. Food Sensitivity Tests Differ From Food Allergy Tests

Just as food sensitivities and food allergies are not the same, neither are the testing methods to diagnose them.

Food allergies are typically diagnosed with a skin prick test. If the immune system releases histamine in response to the suspected allergen, a red bump will appear on the skin, confirming the allergy. Blood tests can also be used. After taking a small blood sample, allergists look for an antibody called immunoglobulin E (IgE) to assess the immune system’s response to specific foods. The presence of IgE antibodies in the blood sample suggests a food allergy.

The most effective way to diagnose food sensitivities is through dietary changes and observation under a health care professional’s guidance.

2. No Single Test Can Diagnose Food Sensitivities

Several leading allergy and immunology organizations agree that no single test can accurately diagnose food sensitivities.

After doing a physical exam and asking about your symptoms, your doctor may recommend an elimination diet. They’ll tell you which foods to avoid and for how long. Although they aren’t perfect, elimination diets can help you and your health care provider link specific foods to symptoms by isolating foods and tracking how you feel when you do or don’t eat them.

3. At-Home Tests Are Unreliable

Research doesn’t support immunoglobulin G (IgG) tests as an accurate way to identify food sensitivities. IgG antibodies are memory antibodies. This means they indicate if you’ve been exposed to a food, not that you’re sensitive to it.

High IgG levels can also indicate an inflammatory or autoimmune disease, an acute infection, multiple myeloma, or another health issue. Misdiagnosing yourself with food sensitivity when something else is causing your symptoms could make your symptoms worse.

Although convenient, at-home food sensitivity tests are unreliable and potentially dangerous. At-home tests should not replace a visit to an allergist or other health care professional.

4. A Food Journal Can Supplement Your Test Results

Some experts recommend keeping a food journal to help identify suspected foods that may be causing your symptoms. Write down what you eat, when, and how you feel afterward. If you notice patterns, discuss them with your health care provider before making any dietary changes.

“Keeping a food and drink journal is extremely helpful for me,” one MyFoodAllergyTeam member said. “Sometimes, a combination of certain foods will trigger an attack. Journaling takes time, but I have found it well worth it.”

For an accurate diagnosis, talk with your primary care provider. Depending on what they find, they may refer you to an allergist, a registered dietitian, a gastroenterologist, or another health care professional. Knowing how and why your body reacts to different foods is the first step toward getting treatment to improve your health and wellness.

Find Your Team

MyFoodAllergyTeam is the social network for people with food allergies and their loved ones. On MyFoodAllergyTeam, more than 40,000 members come together to ask questions, give advice, and share their stories with others who understand life with food allergies.

What is your experience with food sensitivity testing? Have you talked to your allergist or other health care provider about trying an at-home food sensitivity test? Share in the comments below, or start a conversation by posting on your Activities page.