What causes those weird white spots on your nails? We asked the experts

You know what’s annoying? White marks on your nails once you’ve finally given them a breather from all those pretty polishes. A quick dive down the Google rabbit hole can result in some pretty scary stuff. But those white marks on your nails are probably caused by leukonychia, also known as milk spots. Such discoloration requires a rather unremarkable explanation.

Leukonychia is commonly caused by a simple trauma or injury to the nail base, something that you probably don’t even remember doing. “The white marks on nails can make people worry, but they’re most likely the cause of white marks is minor injury, such as being bumped or bitten or knocked on something accidentally,” says Amy Ling Lin, founder of Sundays, a New York City-based non-toxic nail salon.

According to dermatologist Gary Goldenberg, MD, the marks can also be caused by a reaction to nail polish, acrylic nails, or a simple manicure if your cuticles are pushed back too hard at the nail salon. What most people don’t realize is that you might not even notice the marks until a month or so after the injury occurs. Luckily, they’ll eventually go away—even if it takes a little longer than you’d like. “It’s important to note that it may take 3 to 6 months for these spots to grow out,” he says.

Although minor trauma is the most common cause of the white spots, there are some health problems that could be responsible as well. “Infections—such as fungal infection—can also cause white spots, as well as psoriasis, a common skin condition,” says dermatologist Kristina Goldenberg, MD. “Zinc and calcium deficiencies can also be behind white spots.”

If you notice white spots on your nails year-round, it might be worth bringing it up to your doctor to make sure everything is okay. Nail beds are more sensitive than you’d think.

The people who are happiest with their skin share these beauty habits. Or, check out this derm-approved, month-by-month guide to taking care of your skin.