Join the club for FREE to access the whole archive and other member benefits.

Pulse oximeters can give false readings in people with dark skin tone


Key points from article :

Oximeters can overestimate the amount of oxygen in people who have deeper skin tones.

Pulse oximeters send beams of light through the skin to measure oxygen levels in the blood.

The NHS website has been updated with a clarification for oximeter users who have dark skin.

It reads: “There have been some reports [oximeters] may be less accurate if you have brown or black skin.”

“By looking at changes in readings rather than just one reading, it is still possible to see if oxygen levels are going down.”

Review by Cardiff University School of Medicine cites evidence from over 30 years of inaccurate readings for those with deeper skin tones.

Many people suffering from Covid-19 with oxygen levels ranging between 70-80% have been admitted to hospital.

Oxygen levels in the blood can drop to dangerously low levels without the patient noticing, known as silent hypoxia.

People whose oxygen levels have fallen below 92 per cent are urged to go to A&E for medical attention.

NHS suggests to take multiple readings to detect the drop in oxygen levels

Mentioned in this article:

Click on resource name for more details.

Cardiff University

Public Research university.


UK National Health Service, publicly funded healthcare system in England