Allergies and intolerances often cause you to feel tired. Food intolerances and food allergies, in particular, will generally cause tiredness, but other allergies (such as dust, pollen, animal hair, chemicals) can also be a contributing factor. If allergies and intolerances are causing your tiredness, you may also be experiencing one or more of the following symptoms:

• feel tired after eating meals
• feel tired and unrefreshed in the mornings when you wake up
• frequent abdominal bloating, gas, tenderness, indigestion, colic
• prone to chronic constipation, diarrhea or you alternate between them
• hay fever, sinus congestion or asthma
• hives, rashes, eczema or generally itchy skin/scalp
• frequently experience: headaches, dark circles under the eyes, joint pain, hyperactivity.

How do food allergies and intolerances contribute to tiredness?

Food allergies and intolerances lead to tiredness in three main ways.

1. They cause leaky gut syndrome and irritation to the intestinal lining by their presence in the digestive tract. This in turn leads to malabsorption and nutrient deficiencies

2. They place a burden on the digestive system and the body has to use extra energy to try and digest food. This is particularly obvious in people who feel tired after a meal and in some extreme cases, people can even feel tired before they have finished eating.

3. They place an extra burden on the liver. This is because the liver is responsible for processing the nutrients that are absorbed from the food we eat. When you have food allergies and intolerances, these foods aren't digested properly and are sent to the liver to deal with.

What is the difference between a food allergy and intolerance?

There are many different meanings given to these terms and sometimes it simply comes down to a play with words. The generally accepted terminology is as follows:

Food allergy - is a food that triggers an immune reaction. Usually the offending food causes an increase in IgE immunoglobulins (an immune marker for allergy reactions that can be measured in the blood) . This in turn stimulates mast cells to release histamine, resulting in the symptoms of the allergy. Allergy reactions tend to occur quickly after eating the food and are graded depending on the time frame they occur within.

False food allergy - is a food that doesn't trigger an IgE immune response, but directly stimulates mast cells to release histamine.

Food intolerance - is a food reaction that doesn't cause the release of histamine or raise IgE levels. This isn't to say that the immune system isn't involved, and some believe that IgG levels are raised in response to a food intolerance (This is the theory behind cytotoxic food testing that measures IgG responses to foods). Some types of intolerances are caused by a deficiency of an enzyme to digest that food. For example, a person is intolerant to lactose if they lack the enzyme lactase. Regardless of the cause, an intolerant food usually causes symptoms of discomfort. These are typically digestive symptoms (bloating, gas, cramping, diarrhoea) or respiratory symptoms (wheezing, sinus, hay fever). The difficulty with identifying a food intolerance, is that the symptom may not always appear after eating the food. In addition, the symptoms as well as the intolerances can change over time - sometimes even days.

Now you know a bit more about food allergies and intolerances, as well as the role they may be playing in the tiredness that you are experiencing.

So what can you do about it?

• Did you know that there are a number of ways to test for food allergies and intolerances and each has varying degrees of success?

• Did you know that the most effective way to determine food allergies and intolerances is through a test that you can do at home?

• Did you know that food allergies and food intolerances need very different approaches?

• Did you know that removing a problematic food is only a small part of an effective strategy to improve food intolerances?

• Did you know that by reducing allergies and intolerances you are likely to lose excess weight and improve your skin?

You can find out all about these tests and remedies as well as a full list of the symptoms linked to food allergies and intolerances in our e-book Why Do I Feel Tired?

Written by naturopath/nutritionist Alison Cassar and professional health writer Michelle Fahy, this e-book examines over 16 conditions (including food allergies and intolerances) that may be contributing to your tiredness. The book explores each topic in detail and helps you to discover the underlying causes of your tiredness so you can reclaim your energy and live the life you were meant to live.

Most people are unaware of how good they are capable of feeling. There's no need for you to be one of these people. Find out what may be behind your tiredness and get off the merry-go-round of chronic tiredness.

Click here to learn more about this comprehensive e-book and to order your copy.