The most wide spread food allergies are reactions to common foods in our diet. Wheat, peanuts and yeast all cause reactions, sometimes severe, and are found in most of the foods we eat in the US.

If left untreated, food allergies cause a variety of health problems including headaches and ADHD, or Attention-deficit hyperactivity disorder. Some studies link food allergies to cancer, but though tests are still being done, there is not much scientific proof to back up the claims. Many people continue to believe that food cannot be connected with severe illness like cancer.

There are several methods you can use to find out if you have food allergies, ranging from a dietary cleanse to professional allergy tests.

One method is called the elimination diet. You remove wheat and all other grains, eggs, soy, fish, nuts and rice from your diet for three full weeks, as these are all common allergens. After three weeks, if there is no change in your health and you still suffer from allergy symptoms, you remove something else from your diet.

You repeat this, removing one type of food at a time, until your symptoms go away. After you find what you are allergic to, you slowly add back the foods you removed — in case you have more than one allergy. The problems method takes a long time – but it works well if you can stick with it.

The most common method used to test for food allergies is a professional test called a “Scratch” test. Scratch testing is reliable, but not always definitive in results. In scratch testing, small drops of water containing the suspected allergen are placed on the skin and then the skin is scratched very lightly. After 20 minutes, if your skin reacts adversely, you most likely have an allergy to that substance.

There is currently no positive way of telling exactly what you are allergic to and even if you could, allergies often change. If you can avoid a food that you are allergic to for several years, you may be able to eat it again.