As spring brings sunlight and warmth to South Korea, more people can be spotted around the city, taking walks, going on runs or enjoying a picnic by the Han River.

But for some, the season's arrival brings less joy than usual.

Among them is 26-year-old Jeong Seo-yoon, who often struggles with spring allergies that trigger symptoms such as "constant sneezing, runny nose, itchy eyes and the occasional sore throat," she says.

“For me, spring and allergies are like a package deal. You can’t have one without the other,” Jeong told The Korea Herald. “Whenever I feel like my nose is stuffed or that I am sneezing more than normal, that’s when I know spring has arrived.”

The symptoms of allergic rhinitis, also known as hay fever, tend to worsen in spring due to several factors, including seasonal allergens. For example, pollen released by trees and flowers commonly triggers allergic rhinitis by causing inflammation in the nasal passages, leading to the symptoms Jeong mentioned, such as a stuffy nose, sneezing and itchy eyes.

According to Professor Kim Cheol-woo from Inha University’s College of Medicine, who specializes in allergic diseases, the increase in patients with allergies can be attributed to “changes in environmental factors caused by global warming.”

“When air pollutants increase in the atmosphere, the allergens like pollen that trigger such allergic reactions tend to stay in the air for longer,” Kim told The Korea Herald.

“This is because global warming causes trees to release pollen for a longer period, which in turn extends the duration of human exposure to allergens. For people who are prone to allergies, the body becomes more sensitive when pollen levels rise and the immune system reacts more aggressively to the presence of these allergens.”

Kim added that air quality worsened by fine dust pollution can also aggravate allergies, as dust “also lingers for longer due to the higher temperatures.”

“Warmer air tends to slow down the dispersion of pollutants, meaning that fine dust may remain trapped in urban areas like Seoul for longer periods,” added Kim. “This results in higher concentrations of fine dust in the atmosphere, exacerbating allergies.”

According to the National Health Insurance Service, the number of patients visiting hospitals due to allergic symptoms such as rhinitis and asthma has been steadily increasing each year.

In 2023, the number of patients visiting hospitals for rhinitis reached 7.49 million, an increase of more than 2 million compared to 2021. By just June of 2024, the number had already reached 4.46 million.

Also in 2023, the number of asthma patients rose to 1.03 million, and was estimated at 660,000 as of June last year.