COVID-19: How To Use Pulse Oximeters for Accurate SPO2 Readings at Home


COVID-19 has been around for about three years, and it doesn’t plan to leave humanity alone soon. A new variant gains traction every few months and spreads worldwide like the original COVID-19. Now, as the world fights Omicron, we all need to make sure we can take care of ourselves and take accurate SPO2 readings.

If you don’t already have a pulse oximeter at home, we suggest buying one immediately. Doctors recommend regularly using pulse oximeters, as they can help you spot respiratory infections even before you feel out of breath. The earlier one detects a COVID-19 condition, the safer it is for the patient.

This awareness article will look at a few simple steps to teach you how to take accurate and reliable SPO2 readings using a pulse oximeter at home. Let’s begin!

Sit Upright

The first thing to get right is your sitting position. Sitting upright will keep your body relaxed and prevent the irregular flow of blood — preventing inaccurate heart rate and blood oxygen readings.

Insert Your Index Finger  

Place your finger inside the oximeter with the nail facing up. To elaborate, the fingernail would be on the same side as the oximeter’s display. Keep your hand steady for a precise reading, as unnecessary movements can affect accuracy.

Ideally, you should use the index finger on either of your hands as the testing site for an SPO2 reading utilising a pulse oximeter. Make sure you’re not wearing any pigments or nail polish. If the finger has some deformity, use the index finger on the other hand.

Prepare the Oximeter

Before reading, ensure the oximeter isn’t dusty and dirt-free. Sometimes, the photodetector or light source can be covered in dust particles, potentially leading to inaccurate readings.

Before using the pulse oximeter on a covid-infected patient (or potentially infected person with symptoms), try using it on a healthy family member to check if it returns regular readings. If the patient has already used the oximeter, do not use it on a fit family member.

For covid-infected patients, consider using a disposable masimo spo2 sensor to avoid spreading the virus.

Take the Reading

Leave the device on for at least a minute for maximum accuracy before taking your finger out. This allows the device to stabilize and record your readings when your hand is in a state of rest.

Moreover, avoid taking SPO2 readings under direct sunlight or any other direct light source. Since it takes readings based on light transmission, bright lights can affect the sensor’s accuracy. Some other factors, such as shivering or scarring on the skin, can also lead to false readings, so ensure you’re mindful of these factors.


A resting heart rate of 60 to 100 is considered normal. You should take regular heart rate readings to know your normal bpm readings to draw precise comparisons since every human has a slightly different resting heart rate. If the oximeter returns an abnormally high heart rate, stay calm and contact your doctor immediately.

For oxygen saturation, the number should ideally be over 95%. If it starts to dip below 93%, perform regular SPO2 checks and see a doctor if it continues to fall further down.