Can You Really Tell if Someone ‘Looks Sick’?

If you’ve ever had someone look at your face and then ask if you’re sick, you know how disconcerting it can be. Maybe you feel like walking death, but showed up to work anyway thinking you look presentable, or perhaps you actually feel fine, but once someone points out you look unwell, you start to notice that tickle in the back of your throat. But is there any science behind your colleagues’ sickness-detection?

Up until fairly recently, there wasn’t, but new research suggests identifying illness based on someone’s face is actually a thing. Specifically, the findings of the study, published in the journal Proceedings of the Royal Society B, indicate facial cues related to the skin, mouth and eyes can help us detect acutely sick and potentially contagious people.

Here’s how the study worked: Dr. John Axelsson of the Karolinska Institutet, who cowrote the study, and his colleagues injected 16 volunteers with a bacteria designed to trigger their immune systems. The researchers took photos of the participants around two hours after the injection (when they felt the sickest) and then on a completely different day when they received a placebo.

Enlisting help from 60 Swedish university students, the researchers showed them photos of both sick and well participants and asked them to determine whether the person shown was sick or healthy. The students were accurately able to identify the sick individuals in 52 to 70 percent of the photos. They were able to pick out the ill people based on them having “paler lips and skin, a more swollen face, droopier corners of the mouth, more hanging eyelids, redder eyes, and less glossy and patchy skin, as well as appearing more tired,” the study found.

While the student participants were not overwhelmingly able to detect illness in the photos, the researchers noted that our ability to identify whether someone is sick based on the appearance of their face is likely accurate among people we interact with on a regular basis, like friends, family members or coworkers. In those cases, we already have a baseline for what we know they look like normally, so when something changes about their facial appearance, we’re able to spot it faster.

Though the study does not specifically address it, the findings can also be applied to the people who spot a woman who typically wears foundation but for whatever reason skipped a day and proclaim she looks sick. The research does reinforce the fact that as humans, we find other humans who we deem to have attractive faces to be more trustworthy and dominant, so when people — let’s face it, women — are looking in any way droopy or asymmetrical, people notice and assume we won’t be as good at our jobs.

Anyway, makeup aside, the next time someone you see often says “you look sick,” you might want to listen.