Dear Doctor:

When our dad gets sick, he pretty much collapses into bed for a few days. My mom teases him and calls it the “man flu.” To us kids, it’s a family joke, but a friend insists man flu is real. Is she right?

Dear Reader: We’re talking about “man flu” because Dr. Kyle Sue, an assistant professor at Memorial University of Newfoundland in Canada, got tired of being labeled a drama queen when he was laid low by a respiratory infection. According to the definition — and, yes, it’s common enough to have made it into both the Oxford and Cambridge dictionaries — man flu is “an illness such as a cold that is not serious, but that the person who has it treats as more serious, usually when this person is a man.”

The takeaway is that when it comes to getting sick, men can be wimps. But as Sue points out, the assumption that a man with the flu is exaggerating his symptoms and discomfort can inadvertently lead to improper or insufficient medical care. To that end, Sue set out to study man flu. He sifted through various scientific databases using keywords that would cull research related to viral respiratory illnesses and their outcomes in both women and men.

What he found was that, perhaps due to certain physiological differences between the sexes, a man’s immune system appears to react more forcefully to the influenza virus than a woman’s. That may sound like a good thing, but the aches, pains, fever, chills and outpouring of mucus that typically accompany the flu are all courtesy of your immune system’s best efforts. A stronger immune response means worse symptoms.

The differences begin in the test tube. Nasal cells from both women and men were infected with the influenza virus. When the women’s cells were exposed to estradiol, a female hormone, the immune response was more moderate. When the men’s cells were exposed to the same amount of estradiol, the hormone had no effect on the level of the immune response, which was more robust. When it comes to the flu vaccine, the protective antibody response in women appears to be better than in men. One theory links this to testosterone, as men with higher levels of the hormone produced fewer flu antibodies. So even despite a flu shot, a man may still get sick. Other studies that tracked flu-related hospitalizations and deaths found men represented in higher numbers than women. As to the evolutionary advantage to what Sue calls the “immunity gap,” he said more study is needed.

The fact is that in a number of diseases and conditions — including heart disease, osteoarthritis, urinary tract health, stroke, migraine, alcoholism and mental health issues — women and men are affected differently. As for Sue, even as he calls for more research into the subject, he closed his paper with his tongue firmly planted in his cheek:

“Perhaps,” he wrote, “now is the time for male-friendly spaces, equipped with enormous televisions and reclining chairs, to be set up where men can recover from the debilitating effects of man flu in safety and comfort.”