The FDA issued an advisory to healthcare providers and patients warning them not to use pulse oximeters to diagnose COVID-19 or rely solely on the devices to monitor symptoms due to technology limitations.

The FDA issued a safety communication emphasizing the fact that pulse oximeters “have limitations and a risk of inaccuracy under certain circumstances” … “including poor circulation, skin pigmentation, skin thickness, skin temperature, current tobacco use and fingernail polish,” the FDA wrote.

“While pulse oximeters may be useful for estimating blood oxygen levels, these devices have limitations that can result in inaccurate readings. Patients with conditions such as COVID-19 should not rely solely on pulse oximeter measurements to monitor their health at home as they are not a substitute for a medical diagnosis by a health care provider,” William Maisel, MD, MPH, director of the Office of Product Evaluation and Quality, in the FDA’s Center for Devices and Radiological Health, said in a statement.

The FDA’s full recommendations for patients and caregivers using pulse oximetry are available at its website.