MADISON, Wis. -- The start of ragweed season is still weeks away, but local doctors advise ragweed allergy sufferers to be prepared.

Around 75 percent of Americans with allergies are also allergic to ragweed, officials said.

Ragweed are weeds that grow throughout the U.S., but wreak the most havoc in the Midwest. A plant only lives one season, but produces up to 1 billion pollen grains.

Warmth, humidity and breezes after sunrise help release the pollen into the air, officials said.

The allergic reaction to all plants that produce pollen is commonly known as hay fever. Symptoms of hay fever included eye irritation, runny, stuffed up and itchy nose, sneezing and throat irritation, doctors said.

For people with severe allergies, ragweed can trigger asthma attacks, chronic sinusitis, headaches and impaired sleep. Health care professionals said that there is no cure for ragweed allergy, and the best control is to avoid contact with the pollen, WISC-TV reported.

They advise people to stay indoors with central air-conditioning with a HEPA filter when the pollen count is high.

To track the pollen count in the area, they suggest calling the National Allergy Bureau at 1-800-9-POLLEN.

Doctors also suggest antihistamine medications work well to control hay fever symptoms.

They advise that if medication don't give enough relief, allergy shots might be the next course of action. Allergy shots reduce the allergic response to specific allergens, WISC-TV reported.