Eileen Deignan, MD, chief of the Dermatology Department at Emerson Hospital in Concord, Massachusetts, told Best Life that these clear lines, clinically referred to as Beau’s lines, can appear on the fingernails or toenails. “If something stressed the body such as COVID, the nail matrix cells stop growing temporarily,” says Deignan. The lines are a consequence of this pause. “The whole nail matrix is affected as a result of a system-wide illness such as COVID,” she says. “[Beau’s lines] occur as a result of the abrupt stop and then the resumption of nail plate growth. … The depression in the nail is across the whole nail.” Dermatologist Susan Bard, MD, and other experts Best Life spoke with note that Beau’s lines are less likely to follow an asymptomatic or mild COVID infection, but it’s still possible. “Even if you contracted COVID asymptomatically, your body will still be shaken from the viral infection that triggered an immune response,” says preventative global health expert Sandra El Hajj, N-MD. “So, your nails could be affected by this physiological reaction.” RELATED: For more up-to-date information, sign up for our daily newsletter. Beau’s lines can occur any time the body undergoes a significant stressor, says Bard. There’s a slew of other illnesses that can result in Beau’s lines, including diabetes, thyroid disease, pneumonia, chemotherapy, and zinc deficiency, among others, according to Healthline. Deignan notes that these lines could even occur after subtle changes to your system, like having certain vitamin deficiencies or taking new medications. So, if you notice clear lines on your nails, you should talk to your doctor about it. Although there’s nothing they can do for the lines themselves, it’s helpful to know why they grew in the first place. They could mean you had COVID or that you have another underlying illness. RELATED: This Vaccine Reaction Means You May Have Already Had COVID, Study Says. In addition to talking to a medical professional, you should also try to protect your nails in you notice Beau’s lines. “There is nothing specifically to do for COVID nails except protecting the nails as they may be more vulnerable to tearing off at the sight of weakness,” says Deignan. She suggests wearing gloves when washing dishes or doing wet work and keeping your nails and the skin around your nails well moisturized. The lines will disappear when your nails grow out, which Deignan says is about six months for fingernails but could take longer for toenails.
