So, the way allergies work is that if your body is exposed to an allergen and decides that it is harmful to the body, such as pollen, or dander, your body will produce a large amount of the corresponding IgE antibodies, for example, pollen IgE antibodies. The IgE antibodies cause the mast cells to release inflammatory chemicals that cause swelling of tissues, as well as histamine and several other chemicals that cause itching, engorgement of blood vessels, increased secretions, and bronchospasm (tightening of muscles that surround the airways). Some of these chemicals attract white blood cells known as eosinophils. The eosinophils add more inflammatory chemicals. Thus, you react as a defense mechanism.

Helpful Resources: Overview of Allergies This site provides a great overview of what allergies are, what the symptoms are, how you get them, and whether or not you can prevent them. It is very detailed and fairly accurate. Learn More About Allergies This is a great site for learning about allergies. It helps you know if you have a cold or allergies, what your options are for treating allergies, different ways to avoid allergies, and more. Allergy This site provides allergy information, an explanation of what allergies are, and what kind of reaction you will have if you have allergies. It talks about the symptoms of allergies, and how to go about treating them. Wed MD: Allergies This site discusses what an allergy is, what an allergen is, and more. The site provides carious links that indicate what the symptoms are, how to test for allergies, and more. AAFA This site is the allergy and asthma foundation of America. It discusses what an allergy is, and provides links for a library of various texts about allergies and what they are. There are also links for specific allergy types. Allergies This is the about.com take on the question of what an allergy is. This site is very thorough and discusses what an allergy is and provides links for various types of allergies so that you might learn of them. EFA This is the EFA site that discusses what the World Health Organization has to say about what an allergy is, and discusses the immunological side of allergies. It goes on to discuss allergens and more allergy related topics. What Allergy is This site discusses what an allergy is, and why it is what it is. It has links and videos so that you can learn more of what an allergy is and how to treat it. The site offers lots of information for learning about allergies. All About Allergies This site is an easy to navigate site to learning what you need to know about allergies, how to prevent them, how to treat them, and an action plan for dealing with the allergies you have. Claritin This is the Claritin website, it is a site that promotes a specific allergy medication, but it also has a lot of useful information about what an allergy is, and answers to many of the frequently asked allergy related questions.

Now there are different types of allergies, there are airborne, and other. If the allergen is in the air, the allergic reaction will occur in the eyes, nose and lungs. If the allergen is ingested, the allergic reaction will occur in the mouth, stomach, and intestines. If you touch the thing you are allergic to the reaction may manifest on the skin. Sometimes enough inflammatory chemicals are released to cause a reaction throughout the body, such as hives, decreased blood pressure, shock, or loss of consciousness. This severe type of reaction is called anaphylaxis and may be life-threatening.

So, as you can see, allergies are abnormal immune system reactions to things that are typically harmless to most people. When you're allergic to something, your immune system mistakenly believes that this substance is harmful to your body. Thus, to protect your body from the substance, the immune system produces antibodies to that allergen. Those antibodies then cause certain cells in the body to release chemicals into the bloodstream, one of which is histamine. This chemical, histamine, acts on a person's eyes, nose, throat, lungs, skin, or gastrointestinal tract and causes the symptoms of the allergic reaction. While very uncomfortable for the person suffering from the histamine, it is actually a protective response from the body. Future exposure to that same allergen, such as pollen each year, will trigger this antibody response again. This means that every time you come into contact with that allergen, you'll have an allergic reaction.

The level of the reaction depends on your body. For some allergic reactions can be mild, like a runny nose; for others they can be severe, like difficulty breathing. An asthma attack, for example, is often an allergic reaction to something that is breathed into the lungs in a person who is susceptible. If the allergic reaction is very very severe, this is called anaphylaxis. Some of the signs of anaphylaxis are difficulty breathing, difficulty swallowing, swelling of the lips, tongue, and throat or other parts of the body, and dizziness or loss of consciousness.

If you are allergic to something to that degree, your symptoms, or in other words, anaphylaxis, will usually occurs minutes after exposure. There are some cases where a delay is possible, however, in general anaphylactic reactions are rare, and can be treated if you seek immediate medical attention.

Some allergies are simply nasal allergy symptoms and hay fever. This type of allergies are referred to as "allergic rhinitis." Many people suffer from seasonal allergic rhinitis. This describes nasal allergies that change with the seasons due to pollen from plants, trees, weeds, grass, etc. These seasonal symptoms arise and are most severe during the pollinating seasons for particular plants. Because some people are allergic to more than one thing, their symptoms may get worse at different times throughout the year, or they may appear constant (perennial) because there is always some plant that is affecting them.

Not everyone gets allergies, whether or not you get them is a combination of what your genetics are like, as most are inherited, and how strong your immune system is. Most allergies are passed on to children by their parents. People inherit a tendency to be allergic, although not to any specific allergen. However, if you are exposed to an allergen when your defenses are low or your immune system is weak, such as when you are pregnant, or right after a viral infection, this can lead to you developing allergies.

Allergic disorders affect more than 20 percent of adults and children (40 to 50 million people) and are the sixth leading cause of chronic illness in the United States, so there is a good chance that you suffer from allergies if you experience symptoms of allergies regularly. Of course, many people realize that allergy symptoms are similar to a cold, and so how do you know if you have allergies or are simply under the weather? If you think you have allergies, don't wait to see if your symptoms will go away. When your symptoms last longer than a week or two and tend to recur, make an appointment with your doctor so a complete medical evaluation can be performed. Usually your doctor will perform a skin test, also called a prick test. This is usually used to identify the substances that are causing your allergy symptoms. It is exactly like what it sounds. The test is performed by pricking your skin with an extract of an allergen, and then evaluating the skin's reaction.

If a skin test cannot be performed, a radioallergosorbent blood test (RAST) may be taken, although its results are not as accurate as a skin test. Basically this tests to see if you have elevated levels of antibodies for specific allergens.

If you are diagnosed with allergies you may be prescribed medications such as antihistamines, decongestants, or a combination of both. Some of these are available over-the-counter so it is possible to self-diagnose and treat, but it is best to consult a physician. You can also get nasal sprays such as topical nasal steroids and cromolyn sodium which can be used to treat allergy symptoms. Immunotherapy, or allergy shots, is recommended for relief that is needed over a long period of time, such as if you are allergic to your pet but want to keep it.

Allergies cannot be prevented, but they can be treated and controlled. You can you're your immune system high in order to prevent developing additional allergies. However, making changes in your environment can greatly limit your exposure to certain allergens and reduce your symptoms.

Allergies are not fun, and can be caused by foods, dust, dander, pollen, and any number of other things. If you think you may have allergies talk to your doctor. The symptoms can be treated and you can live a happy symptom free life, but only if you take the time to check and see if your stuffy nose or watery eyes are allergies not just a common cold.