Which do you have?
A food sensitivity is when your body has trouble digesting certain foods. With a food sensitivity small amounts of the problem food usually do not cause symptoms. With my food sensitivities, the more I eat of something the more sensitive my body becomes. Symptoms also don’t show up right after eating. It can takes hours – even up to 48 hours after eating the food. This makes it hard to diagnose which foods you might be sensitive to. There is a blood test that a doctor can do to determine food sensitivities where your IgG (Immunoglobin G) antibody levels are checked. That is how my food sensitivities were diagnosed. I have read that these tests are not always consistent or even accurate. However, for me when I avoid the foods that showed up as sensitive I feel much better. No more headaches and ulcer-type feelings in my stomach!
A food allergy triggers the immune system and results in a histamine reaction. It usually only takes a small amount of food to cause a reaction. And the reaction is usually (but not always) fairly quick. Most people with food allergies are aware that they have them because they cause symptoms such as rashes, tingling mouth, swelling or anaphylaxis. Food allergies can be diagnosed with a skin prick test.
Note: I am not a medical professional. The information included in this post comes from years of personal experience, reading and researching.