How-to guide · Fingertip pulse oximeters
How to use a fingertip pulse oximeter and read the display
Get your hand ready, place the sensor as directed, and wait for the numbers to settle. Then identify the oxygen saturation estimate and pulse rate.
Which hand and finger should you use?
Follow the placement diagram in your model’s manual. Use a finger that fits securely without squeezing. If a healthcare professional asked you to use a particular finger or position, follow that guidance.
The FDA recommends keeping your hand warm, relaxed, and still. Remove nail polish from the finger you use and check the supported size if the clip does not fit.
What the display shows
SpO₂ is estimated oxygen saturation. PR is pulse rate in beats per minute. Some models also show a perfusion index or a waveform that describes the signal at the finger.
Display orientation, brightness, and number placement depend on the model. To compare screens, check the exact product and its manual.
Before you start
Check the batteries and the sensor. If you plan to keep a log, have a sheet of paper or the supported app ready. If you were asked to monitor at home, review your healthcare professional’s instructions.
How to take a reading in five steps
- Support your hand so you can keep it still.
- Place your finger as shown in the manual.
- Turn on the device according to the instructions.
- Wait for the numbers to settle.
- Record the SpO₂, pulse rate, time, and circumstances.
If there is no reading or the number changes
Movement, temperature, circulation, nail polish, and skin pigmentation can affect a reading. Check the fit and review the manual. If symptoms are severe or worsening, seek medical care without relying on an isolated reading.
| Situation | What to check |
|---|---|
| The numbers keep changing | Keep your hand still and wait for the numbers to settle. |
| There is no reading | Check the batteries, placement, and fit as directed in the manual. |
| You want to compare several readings | Record the time and circumstances of each reading. |
Frequently asked questions
Can I use any finger?
Check your model’s instructions and make sure the sensor fits.
Is pulse rate the same as oxygen saturation?
SpO₂ estimates oxygen saturation. PR reports pulse rate separately.
What does the perfusion index show?
It describes part of the signal detected by the sensor.
FDA: pulse oximeters and their limitations