How It's Measured
Counting centers use microscopes to count grains of pollen, says Mike Seidel, a meteorologist for The Weather Channel. Then the pollen-count level is categorized (green, yellow, orange, or red) for each type of pollen mold, grass, tree, or weed).
When You Feel It
People with allergies will feel symptoms when the count tips into the yellow range.
What to Do
Because pollen counts are highest from 2 a.m. to 10 a.m., don't sleep with your windows open, advises Dr. Pamela A. Georgeson, president of Kenwood Allergy and Asthma Center in Chesterfield Township, Michigan. Run the air conditioner to filter allergens. Before bed, take a shower to remove pollen that may be sticking to you.
Where to Look
Refer to the American Academy of Allergy, Asthma and Immunology site at aaaai.org to find pollen-counting centers near you.