This Is What Really Happens Underneath Your Fingernails If You Don't Clean Them

It can often feel like you only need to take your eyes away from your fingernails for just a second for some gunk to accumulate underneath them. Sure, it can get pretty annoying, but is it harmful? And just what is that gunk?

Fortunately, for the most part, the grime you get under your nails isn't anything to worry about. As dermatologist and nail health expert Dana Stern told Women's Health, "The 'gunk' underneath fingernails is most commonly the keratin debris from the underside of the nail, as well as skin cells from the nail bed." Alongside skin cells and keratin debris, there might be a bit of lint, maybe traces of some of your favorite hand care products too, and yes, a bit of dirt. So far, so harmless.

However, we're constantly touching different things each day. When we use the bathroom, prepare food, and take public transportation, we're coming into close contact with all sorts of germs. Let's take a closer look at what really happens underneath your fingernails when you don't clean them.

You could get "the greenies" under your nails

The gunk under your fingernails will typically be gray in color. If it turns green, however, it can signal bacteria (via Women's Health). Nevertheless, bacteria isn't an uncommon finding under the nails. In a 2017 study of 20 students, which was published in the International Journal of Current Microbiology and Applied Sciences, every single one had bacteria underneath their nails, from pseudomonas to staphylococcus to bacillus. Not one student had bacteria-free fingernails.

"Pseudomonas ... is commonly found on nails and produces a green pigment that nail technicians often refer to as 'the greenies,'" dermatologist Dana Stern told Women's Health. Iron compounds cause the trademark green color, and the infection tends to occur in moist environments, making nails an ideal location (via Nails).

It's particularly prevalent with artificial nails, for a couple of reasons. Not only do false nails have little openings in which bacteria can thrive, but they're longer too, according to Stern. This makes it far easier to attract the bacteria in the first place. As we saw from the study of students, attracting bacteria is unavoidable, but you can at least address the problem before it gets too serious.

How can you keep your fingernails clean?

So, what can you do to keep your nails clean and reduce the risk of any unsightly infections? Dr. Philip Tierno, a clinical professor of microbiology and pathology at NYU Langone Medical Center, told Mic, "Eighty percent of all infections are transmitted through contact, direct or indirect." He continued, saying, "The fingers are the 10 dirtiest things on your body." As obvious as it might sound, washing your hands frequently is half the battle.

As we're always coming into contact with things that other people have touched, washing and scrubbing your hands to the tune of "Happy Birthday" — twice  — is the way to go to kill germs. When using hand sanitizer, make sure you scrape your nails on the palm of your hand so that they get some of the gel for themselves. And if you're dealing with food, Tierno recommends using a soapy brush to clean underneath your fingernails.

Keeping your fingernails short is helpful, as it gives bacteria less room to hide, according to dermatologist Dana Stern (via Women's Health). She also advised "digging your nails into a bar of white soap" while in the shower, as part of your regular hygiene routine. It might take you a few extra minutes in the bathroom, but that's surely a small price to pay for squeaky clean fingernails, right?