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Allergies Health Center

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Frequently Asked Questions About Allergies

Print these allergy questions and answers to discuss with your doctor.

What Types of Plants Produce the Most Allergy-Causing Pollen?

The type of pollen that most commonly causes allergy symptoms comes from plants (trees, grasses, and weeds) that typically do not bear fruit or flowers. These plants produce small, light, dry pollen granules in large quantities that can be carried through the air for miles.

Common plant allergens include:

  • Weeds, such as ragweed, sagebrush, redroot pigweed, lamb's quarters, goosefoot, tumbleweed (Russian thistle), and English plantain
  • Grasses, such as timothy grass, Kentucky blue grass, Johnson grass, Bermuda grass, redtop grass, orchard grass, sweet vernal grass, perennial rye, salt grass, velvet grass, and fescue
  • Hardwood deciduous trees, such as oak, ash, elm, birch, maple, alder, and hazel, as well as hickory, pecan, and box and mountain cedar; juniper, cedar, cypress, and sequoia trees are also likely to cause allergy symptoms.

What Does a Pollen Count Mean?

A pollen count is the measure of the amount of pollen in the air. Pollen counts are commonly included in local weather reports and are usually reported for mold spores and three types of pollen: grasses, trees, and weeds. The count is reported as grains of pollen per square meter of air collected over 24 hours. This number represents the concentration of all the pollen in the air in a certain area at a specific time. The pollen count is translated into a corresponding level: absent, low, medium, or high.

In general, a "low" pollen count means that only people extremely sensitive to pollen will experience allergy symptoms. A "medium" count means many people who are relatively sensitive to pollen will experience allergy symptoms, and a "high" count means most people with any sensitivity to pollen will experience allergy symptoms.

Although the pollen count is an approximate value and fluctuates, it is useful as a general guide when you are trying to determine whether or not you should stay indoors to avoid pollen contact.

Should I Consider Moving to Decrease My Allergy Symptoms?

No. Moving to a different geographic climate will not help "cure" allergies or allergy symptoms. Most people who relocate to get away from pollens that cause their allergies tend to find that they eventually develop allergies to the plant pollens in the new area.

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