Men and women really are different—and it turns out, our bodies even react differently to diseases.

Ladies, get ready. Man flu season is coming. 

In case you're new to this phenomenon, Urban Dictionary tells us, “Man flu (mæn flu): an illness that causes the male species to be helpless and sicker than any other family member. In females; a cold.

Yes, we've all probably rolled our eyes at the helplessness of the men in our lives when they're sick. We’ve exchanged our confusion with our girlfriends, laughed at memes, chuckled at video parodies, and may have even stumbled upon this cheeky ManFlu website, plastered with ridiculous stock photography and gibes that never seem to get old.

But it turns out—maybe our guys aren't being as overdramatic as we thought. While the research is far from conclusive, evidence in recent scientific studies suggests that the average dude might not be making up the seriousness of his symptoms. As part of a larger study, psychology professor Nafissa Ismail, director of the NISE (NeuroImmunology, Stress and Endocrinology) Laboratory at the University of Ottawa and her team may have answered one of modern medicine’s many quandaries: man flu may very well be a real thing.

Ismail and her fellow researchers began infecting groups of mice with LPS (Lipopolysaccharide) to induce symptoms of the human flu. Ultimately, the adult male mice became far more miserable than their female counterparts. Their bodily temperature fluctuated more than the females', they had a larger loss of appetite, and visibly became more lethargic as they huddled together in their sickness—droopy eyelids and all. The male mice ultimately took an average of forty-eight hours to recover, whereas the female mice only took twenty-four hours.

Ismail told Metro News, “We were really surprised, and at first, we were like, ‘Is this real?”

Ismail explained that she believes this difference is due to the fact that testosterone (a sex hormone that is more prominent in men) and estrogen (more prominent in women) affect the immune system differently. Estrogen has been known to boost the immune system, so while women may initially feel worse, we generally have a speedier recovery. Testosterone, on the other hand suppresses the immune system—which can elongate the illness, making the experience far more miserable for our fellow man.

Yet every rose has its thorn. While women may recover faster from flus and colds, we are actually far more likely to have an autoimmune disease; that’s a fact. Women comprise nearly 80% of those who suffer from autoimmune diseases. Although evidence on the effects of hormones in this case are inconclusive, one theory is that since estrogen has a more intense response to infections, female immune systems have a tendency to become more hyperactive and start attacking healthy cells. In sum, what makes us women recover faster from flus and colds, according to this theory, can actually backfire on us by an overcompensating immune system.

A secondary theory points out that since women have two X chromosomes—the chromosome that carries more influence on our body’s autoimmunity—our bodies aren’t consistent in deciding which X chromosome in our cells is inactive or notDr. Karl of ABC Science explains it this way: "[a woman's body] inactivates the X chromosomes on almost a random basis, so one cell might use the X chromosome from her father, while the cell right next it might use the X chromosome from her mother." Cells with two different X-chromosomes might fight each other as if the other were an infection.

Neither of these theories are entirely conclusive studies—not even the man flu, as mice certainly aren't the same as humans. But scientists use mice to predict human response because they closely repeat human diseases. When we take this into account, the research does suggest that gender plays a role in how our bodies respond to illness, which is something to remember when we’re comparing our physical experiences with men. They'll never understand our PMS, and we’ll just never truly know the pain they experience. Instead, we'll just have to focus on finding joy in caring for each other when all systems aren't functioning at 100 percent.