Working over 13 hours a day may double the risk of having a brain hemorrhage, a research paper published in the International Journal of Stroke showed Wednesday.

According to a study conducted by neurology professor Kim Beom-joon at Seoul National University Bundang Hospital in Seongnam, Gyeonggi Province, those who worked for more than 13 hours a day had a 94 percent higher chance of having a cerebral hemorrhage than those working for four hours a day.

Kim analyzed the occupational types, working hours and work intensity of 940 brain hemorrhage patients and some 1,900 workers who had never had the disease.

Those who work for 9 to 12 hours a day, the most common amount of working hours in Korea, had a 38 percent greater risks of the disease.

High work intensity was one of the major risk factors for the disease, the study showed.

Those who performed physical work for over eight hours a week had a 77 percent higher chance of a cerebral hemorrhage. Reducing the amount of physical work by one hour decreased the risk by 30 percent.

Blue-collar workers had a 33 percent higher risk of the disease than white-collar workers.

“The increase of work intensity may raise the stress level, and ultimately the blood pressure, which leads to a higher risk of a brain hemorrhage,” Kim said.

“Laborers with loads of work may worsen the state of their health by not having enough rest. Some may not even have enough time to see a doctor even if they have high blood pressure.”

Those with high blood pressure should refrain from overworking, smoking and drinking alcohol in order to reduce the chance of a brain hemorrhage, Kim stressed.

The medical expert also added that sufficient exercise, rest and sleep after work are crucial for a healthy life.

By Lee Hyun-jeong (rene@heraldcorp.com)