What is the most accurate pulse oximeter?

A pulse oximeter estimates oxygen saturation and pulse rate through a fingertip sensor. Cold hands, movement, nail products, poor circulation, an irregular pulse or an incorrectly positioned sensor can make the displayed value unstable. Skin tone and device quality may also affect readings. A single number is not a diagnosis.

Learn how the [Pulse Oximeter](/technology/pulse-oximeter/) works and why a reading should be considered with breathing, chest comfort, alertness and skin colour.

Rest quietly, warm your hand and remove artificial nails or dark polish if possible. Place the device securely on a finger, keep your hand still and wait until the number and pulse signal settle. Repeat an unexpected reading on another finger, then record the value and your symptoms. Do not change prescribed oxygen or medication based only on the screen. A [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) can help interpret repeated concerns.

Seek urgent medical help for severe breathlessness, blue or grey lips, chest pain, confusion, fainting or inability to speak in full sentences. Get advice promptly if readings remain concerning or fall while you feel unwell, even if the device appears to be functioning normally.

Ask which readings are expected for you, how often to monitor, what symptoms should override a device reading, and whether your device and technique are suitable for your condition.