What is ragweed? And why does it cause allergies in the late summer?

While our summer has been dry, many can't say the same for their nose or eyes. Ragweed allergies are picking up steam.

"Ragweed is actually a very, very common weed that grows wild throughout the Midwest and Northeast," said Dr. John Sweet, an allergist with Hennepin Healthcare.

Its leaves have a fern-like appearance with greenish-yellow flowers at the end of its branches. Sweet said just one single ragweed plant can generate a billion grains of pollen that can travel more than 100 miles.

"Even though you may not see ragweed in your yard, it's in the air. So, there's almost no avoiding it when you're outside if you have an allergy," he said.

Seasonal allergies impact about 20% to 40% of the general population, according to Sweet.

When ragweed pollen gets into an allergic person's eyes, nose or throat, the body releases chemicals to fight it, creating the following symptoms:

• Itchy, watery, red eyes
• Nasal congestion
• Runny nose
• Eczema/hives

"Other people can have sensitivity in their lungs where they start having asthma symptoms. They start having coughing, wheezing, chest tightness," added Sweet.

The symptoms start appearing in August and peak in September because that's when ragweed blooms and releases pollen.

Unfortunately, Minnesota's drought conditions aren't helping the situation. As grass burns and struggles to grow, weeds thrive along with their pollen.

"And if you combine that with some heavy winds, the pollen counts just will soar in those days," Sweet said.

Rain would be helpful since it washes pollen away to prevent it from flying in the air. But it also helps ragweed grow, meaning it would release more pollen later in the season.

So how can you best battle ragweed allergies?

It's starts with prevention. Sweet says you can use a steroid nasal spray and take an antihistamine pill daily, though you should do it before symptoms start.

"(Nasal spray and allergy pill) combined can be much more effective than taking either separately," he said.

Ragweed pollen also sticks easily to hair and skin. Sweet recommends showering to remove it, especially before getting into bed.