This device is crucial in the fight against Covid. It may not work on dark skin

A pulse oximeter is attached to a patient's finger to monitor oxygen intake within the body, at EHA Clinics in Abuja, Nigeria January 14, 2021.

(CNN)In the fight against Covid-19, the pulse oximeter has been an essential tool for doctors and other medical professionals. But the small device that monitors oxygen levels may not work well for people with dark skin, according to multiple studies and government health agencies.

Pulse oximeters, which have increased in use during the pandemic, may yield inaccurate results, the US Food and Drug Administration warned Friday.
Earlier in week, the US Centers for Disease Control and Prevention also updated its coronavirus clinical guidance to warn doctors and nurses that data from several studies suggest skin pigmentation can affect the accuracy of the devices.