Allergy sufferers may feel a little under the weather, and they can blame the weather. Thunderstorms early this week stirred the allergen pot, experts say.

When a thunderstorm rolls through, the winds stir up both mold spores and tiny particles released by pollen grains. It starts while the sun is still shining, says Dr. Richard Weber, an allergy specialist with the National Jewish Medical and Research Center in Denver. "It has to do with updrafts that often precede thunderstorms. They cause mold spore counts to go up astronomically, 100 times higher than normal."

As the storm passes through, winds also disrupt the grass pollen grains on the ground, causing them to release tiny particles - particles that are 1,000 times smaller than the pollen grains, says Weber. "The particles don't show up on any pollen count. But a wave of cold air will sweep the stuff off the ground - blow it just high enough to hit people in the face." Because the particles are so tiny, they are inhaled deeply into the lungs causing serious problems, he explains.

One thunderstorm can cause "a double-whammy before the storm rolls through, then afterward," Weber says. "Those fine particles can be very irritating."

Source: WebMD.com