Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein.

Pulse oximeter

A pulse oximeter is a device that checks to see how much oxygen is in the blood.

A small clip is put on a finger, toe, or earlobe. The light beam in the clip measures the oxygen of the red blood cells that move through the cells in the finger, toe, or earlobe. The person's oxygen level can be read on the display. A pulse oximeter often has an alarm for blood oxygen levels that fall below a safe level.

Pulse oximeters are used in doctor's offices and hospitals. You can also buy one for home use. This may be a good idea for people who have a condition that affects their oxygen levels. This includes some people who have long-term heart or lung problems. The device may identify a low blood oxygen level before it causes symptoms.