One in five people come down with allergy symptoms that if left untreated can make them miserable.
And every year, it's tree pollen that's the culprit. It is carried by the wind to pollinate other parts of the same tree, to make seedlings.
"It's got a purpose. We just happen to be innocent bystanders affected by this pollen," said Rhode Island Hospital allergist Dr. Russell Settipane.
It's not the pollen from vibrant flowering trees or flowers themselves that make those with allergies suffer. That pollen is not airborne and requires bees.
And while over-the-counter medications work for those with mild symptoms, identifying what pollen you're allergic to for those with severe reactions is essential.
"You need to get in and get specific treatment particularly through nasal sprays that really can really nip this thing in the bud, so to speak, and prevent you from getting severe," Settipane said.
The only reason why it's good to know what you're allergic to is because different things pop at different times of the year.
"The trees kind of pollinate sequentially, one after another, starting off with the elm and maple trees in early April, but now we're on the cusp of the oak and birch pollen season, which produce a tremendous amount of pollen over the next three to four weeks," Settipane said.
And the pollen from birch and oak is the one that most people are allergic to.
"About 70 percent of people with nasal allergies, pollen allergies, will have associated eye symptoms, and there's allergy eye drops that are directed specifically to reduce the eye symptoms," Settipane said.
After May's tree pollen, comes June's grass pollen. There's a break in July, but then ragweed and wheat pollen come August through October.
But allergists say once it's identified what you're allergic to, better drugs are available to ward off the symptoms before they start.