Allergies Health Center

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.

Ragweed Facts

• Ragweed causes allergy symptoms like stuffy or runny nose, sneezing, and itchy eyes. It can also trigger asthma flares.

• People who have ragweed allergies are reacting to its powdery pollen. During ragweed season, one plant can release a billion grains of pollen into the air.

• Ragweed is worst on dry, windy days. Pollen counts are lower when it's chilly, windless, humid, or rainy.

• 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. 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.

Treating Ragweed Allergies

Staying away from ragweed will help but may not be enough. You may benefit from:

• Testing, to make sure that you really have a ragweed allergy.

• OTC medications, which ease ragweed allergy symptoms.

• Prescription medicine, which controls your allergies, lowering the risk of a flare-up.

• Early treatment. If your doctor says it's OK, start taking medications two weeks before ragweed season starts. That way you can stop the allergic reaction before it starts.

• Allergy shots, which can -- over the course of months or years -- get your body used to ragweed, so it no longer triggers an allergic reaction.