(CNN) -- A Canadian researcher says "man flu" is real after he said he was "tired of being accused of overreacting."
According to research published Monday in the BMJ medical journal, men are more susceptible to complications than a woman, and men's immune systems may be naturally weaker.
CNN reports the term "man flu" came about as a way to chide men who have been suspected of exaggerating the severity of symptoms related to colds or illnesses.
"It's a frequently heard stereotype," Dr. Kyle Sue, author of the study, said.
Sue began researching the stereotype, and he found a good amount of evidence that was "suggestive of an immunity gap," though he said his findings were "certainly not definitive."
One of Sue's first points argued that women have a different response to vaccines that protect against the flu.
"There are a couple of studies that show women having more local and systemic reactions to the flu shot than men," Sue said. He also said the evidence suggested women may be "more responsive to vaccinations than men."
"Epidemiologic data from Hong Kong showed that adult men had a higher risk of hospital admission for flue," Sue said. An American study found that men died more often from flue compared with women of the same age, regardless of other outlying conditions.
"However, neither study differentiated men and women based on other differences, like smoking and drinking rates (and) willingness to seek medical help," he said. He also said those unknown rates may have influenced study results.