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Allergies Health Center

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Ragweed Allergy

If your allergies flare up in the late summer or early fall, there's a good chance you're allergic to ragweed. Ragweed is the most common trigger for hay fever. About 1 out of 5 people are allergic.

Here are some key facts about ragweed -- and advice on how to control your symptoms.

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Ragweed Facts

  • People who have ragweed allergies are reacting to its microscoptic pollen. During ragweed season, one plant can release a billion grains of pollen into the air.
  • Ragweed is worse when nights are cool and the days are warm and dry.
  • Ragweed season usually starts in early August and ends in mid-October. Some researchers think ragweed season may be lasting longer because of climate change.
  • Ragweed is everywhere in the U.S.. It's most common in the East and Midwest, but it's in every state. Because it's so light, the wind carries ragweed pollen far. Researchers have found ragweed pollen two miles up in the atmosphere and 400 miles out at sea.

Limiting Contact With Ragweed

Avoiding ragweed may be impossible. But there are ways to limit your exposure -- and lower your risk of symptoms. During ragweed season you should:

  • Avoid peak ragweed hours. Limit your time outside between 10 a.m. and 3 p.m. Ragweed counts are lower in the early morning and late afternoon.
  • Track pollen counts. Check them in the newspaper or on the Web. Stay inside when they're high.
  • Keep windows closed. At home and in the car, don’t open the windows. Using central air-conditioning with a HEPA filter will not only keep you cool, but also help filter out pollen.
  • Change your clothes and wash your hands after you've been outside. Ragweed can stick to skin or clothing.
  • Watch out for food triggers. Eating foods that contain similar proteins to ragweed pollen proteins can worsen symptoms. Bananas, melons, honey, sunflower seeds, and chamomile tea can trigger symptoms.
  • Don't dry laundry outside. It will pick up ragweed pollen. Dry your laundry in a dryer.

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