An allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment.

A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid. Allergy is one of four forms of hypersensitivity and is formally called type I (or immediate) hypersensitivity.

Mild allergies like hay fever are very common in the human population and cause symptoms such as red eyes, itchiness, and runny nose, eczema, hives, or asthma. In some people, severe allergies to environmental or dietary allergens or to medication may result in life-threatening reactions called anaphylaxis.

Treatments for allergies include avoiding known allergens, use of medications such as anti-histamines that specifically prevent allergic reactions, steroids that modify the immune system in general, and medications such as decongestants that reduce the symptoms.

-- from wikipedia.org

The following articles provide a more indepth look at the causes and treatment of allergies.

Acupuncture for Acne, Psoriasis, Allergies
Acupuncture for acne, psoriasis, allergies and other related conditions is the current interest of several study groups, aiming to investigate and validate the preliminary studies on the effects...

Allergies
Allergies are so common 20% of Americans have some kind of allergic reaction or another to certain external stimuli whether food, water, or air.

Allergy and Sinus Relief
A lot of people who suffer from sinusitis say that the condition is a huge pain in the nose.

Allergy Medicine
Allergy medicine can provide much-needed relief to allergy suffers. This article reviews the basics of allergy medication.

Allergy Products
Allergies are prevalent these days, not only in children but in adults as well. In fact, according to the FAAN (Food Allergy and Anaphylaxis Network) the prevalence of allergic reactions to peanuts has doubled over a period of five years.

Allergy Relief
Today, there are approximately 44 million people in the United States of America suffering from allergies and the numbers are increasing.

Allergy Relief Air Purifier
About ninety percent of Americans spend majority of their time indoors, without knowing that the air inside the home can contain potentially harmful airborne contaminants as much as air...

Allergy Relief Medicine
There are many different types of medicine and treatment used to give you allergy relief.

Allergy Relief Product
Allergy relief products are a multimillion dollar industry. But how are you to know which allergy relief product works?

Allergy Symptoms
You known you're allergic when you react to certain substances you've been exposed to before.

Food Allergies
Ever eaten something that made you break into rashes? How about itchiness of the throat, around the eyes, your ears, and even your hands and feet? These are actually symptoms of food allergies.

Food Allergy
Each year hundreds of people die from food allergy and other allergies. Over 30,000 receive life-saving treatment in emergency rooms due to food-induced anaphylaxis.

Gluten Allergy
However, much of the alarm over gluten allergy and gluten intolerance is unnecessary, not to mention unfounded, since a lot of aspects of these two conditions remain largely misunderstood.

Latex Allergy
An increasing number of Americans are becoming allergic to latex, a natural substance derived from the milky sap of the rubber tree.

Mold Allergies
A single mold spore is a tiny, microscopic little thing that usually thrives in damp places. Yet for its diminutiveness in size, mold spores can be deadly to people who have allergic reactions to them.

Peanut Allergy
A peanut allergy is one of the most common food allergies because the proteins found in peanuts can act as powerful allergens, even when ingested in tiny amounts.

Skin Allergies
Skin allergies are one of the most common causes of conditions of the skin. They are typically caused by a problematic immune system which becomes hypersensitive after being exposed to a...

Wheat Allergies
Wheat is the staple of majority of American diets. But due to the recent furor about wheat allergies and its potentially deadly consequences, people have been randomly taking out these foods from their diet to the detriment of their own health.

Wheat Allergy
True wheat allergy is extremely rare. And other adverse reactions to wheat are also uncommon.