What Are Allergies and What Causes Them?

You have an allergy when your body overreacts to things that don't cause problems for most people. These things are called allergens. Sometimes the term "hay fever" or "rose fever" is used to describe an allergic reaction to allergens in the air. Your body's overreaction to an allergen is what causes allergy symptoms (see the box below).

Common symptoms of allergies:

  • Runny nose

  • Watery eyes

  • Itchy nose, eyes and roof of mouth

  • Sneezing

  • Stuffy nose

  • Pressure in the nose and cheeks

  • Ear fullness and popping

  • Dark circles under the eyes

  • Hives

How Can I Avoid Problems?

It is not easy to avoid most allergens. To avoid suffering with a runny nose and sneezing, try to figure out what allergens cause problems for you. Then stay away from them as much as possible. Here are some tips on how to avoid common allergens:
  • Pollen from trees, grass and weeds - Shower or bathe before bedtime to wash off pollen in your hair and on your skin. Avoid going outside during the time of year when your allergies cause the most problems, especially on dry, windy days. Keep widows and doors shut at home and in your car, and use an air conditioner. Special air filters, such as HEPA and eletcrostatic filters, can help reduce allergens in the air.

  • Mold - Remove houseplants. Frequently clean shower curtains, bathroom windows, damp walls, areas with dry rot and indoor trash cans. In areas where mold has built up, use a mixture of water and chlorine bleach to kill it. Don't carpet bathrooms or other damp rooms. Use mold-proof paint instead of wallpaper. Reduce the humidity in your home to 50% or less.

  • Pet dander - If your allergies to dander (skin and hair from animals) are severe, you may need to give your pets away, or at least keep them outside.

What Medicines Can I Take to Help Relieve My Symptoms?

If avoiding allergens doesn't help enough, you may need to try allergy medicines. Some common types are described below:

  • Antihistamines help reduce sneezing, runny nose and itchiness. Antihistamines that you can buy without a prescription relieve symptoms just as well as prescription medicines do. However, they tend to cause tiredness and dry mouth. Prescription antihistamines are less likely to cause tiredness or dry mouth. Before you take an allergy or cold medicine, check the label for a drug called phenylpropanolamine, or PPA. The U.S. Food and Drug Administration recently recalled this drug for safety reasons. If a medicine contains PPA, don't take it.

  • Decongestants help temporarily relieve a stuffy nose. They come as pills, nose sprays and nose drops. Decongestant tablets or liquids are best used only for a short time (1 to 2 weeks). Nose sprays and drops shouldn't be used for more than 3 days because your body can become dependent on them. This causes your nose to feel even more stopped-up when you stop using them. You can buy decongestants without a prescription. However, decongestants can raise blood pressure in some people, so it's a good idea to talk to your family doctor before using them.

  • Cromolyn sodium is a nasal spray that helps prevent your body from reacting to inhaled allergens. Cromolyn sodium is more helpful if you use it before you're exposed to allergens. This medicine may take up to 2 to 4 weeks to start working. It is available without a prescription.

  • Nasal steroid sprays reduce the inflammatory reaction of your nasal tissues to inhaled allergens. Your doctor may prescribe a steroid spray to relieve the swelling in your nose so that you feel less stopped-up. this medicine may take a couple of weeks to start working.

  • Eye drops can help itchy, watery eyes. You can buy these drops without a prescription. Your doctor may suggest eye drops that contain an antihistamine-decongestant combination. These drops are available in over-the-counter and prescriptions forms. Be sure to read the directions before using any medication. Many of these eye drops should not be used for longer than a few days.