Yes remove all nail polish before any surgical or medical procedure that involves anaesthesia. This includes regular polish, gel, shellac, and acrylic overlays. The reason is not bureaucratic caution: your bare nail beds are how the surgical team monitors your oxygen levels while you are unconscious, and anything covering them can compromise that reading.
The device at the centre of this is the pulse oximeter the small sensor clipped to your fingertip during surgery and recovery. It works by passing beams of red and infrared light through your nail bed to measure how much oxygen your blood is carrying. Polish absorbs and scatters that light. Dark shades, particularly black, brown, and deep navy, have been shown in clinical studies to produce significantly inaccurate readings. Gel and shellac manicures present a particular problem because of their thickness: a 2019 study published in a peer-reviewed anaesthesia journal found that gel polish can cause the oximeter to overestimate oxygen levels, which is the more dangerous outcome. You appear fine on the monitor. You may not be.
Most people who ask this question are asking because they have a fresh gel manicure and are hoping there is a workaround. There is not one worth relying on. Surgical teams can reposition the sensor to your earlobe in an emergency, but that is not a substitute for clean fingernails going in. If you arrive at hospital with polish on, the nursing staff will remove it for you before you go into theatre which means arriving with acetone applied at home is simply more dignified.
What most guides on this topic quietly skip is that the rule applies to toenails too, for longer procedures where additional monitoring sites may be used. It also applies to acrylic nail extensions and nail tips, not just polish. Anything that sits over the natural nail plate interferes with the sensor's ability to pass light through cleanly.
The only type of nail that genuinely raises no concerns is a short, bare, clean natural nail. If you are preparing for surgery and currently wearing a gel or shellac manicure, book a soak-off appointment as early as possible gel removal done properly takes time, and rushing it or peeling it at home can leave your nail plate damaged and thin. Give your nails a few days to settle before your procedure date if you can.
Your surgeon will have a pre-operative checklist. Removing nail products before surgery sits alongside fasting and stopping certain medications it is clinical preparation, not cosmetic inconvenience. Bare nails on surgery day are the correct nails.
