PariwellHow to use a pulse oximeter at home, and what the numbers mean
How to get a reliable oxygen reading from a fingertip pulse oximeter, the normal range, what can make it wrong, and when a low reading needs a doctor.
A fingertip pulse oximeter shows two numbers: SpO2, the percentage of oxygen in the blood, and the pulse (heartbeats per minute). It's a useful home check for parents with lung or heart problems, or during an illness like a chest infection.
What's normal
- For most healthy people, SpO2 is 95% to 100%.
- People with long-term lung or heart disease may normally run lower. Their doctor will tell you what's normal for your parent. That number matters more than any chart.
- A change is often more important than the number itself: if your parent is usually at 97% and is now at 93%, tell the doctor.
How to take a reliable reading
- Rest for 5 minutes, sitting down.
- Warm the hands first. Cold fingers give low or no readings.
- Remove nail polish or artificial nails from that finger.
- Put the oximeter on the index or middle finger, with the hand resting on a table at chest level.
- Stay still and quiet, and watch until the number stops changing, usually within a minute. Note the steady number, not the first one.
Things that can make the reading wrong
- Cold hands or poor circulation
- Moving or shivering during the reading
- Nail polish, henna or artificial nails
- Very bright light on the sensor
- Darker skin: oximeters can show a higher number than the true oxygen level, so trust symptoms over the device
- Smoking shortly before
When to get help
Call the doctor the same day if the reading is lower than your parent's usual, or keeps dropping.
Keeping track
Write down the number with the date and time, or send a photo of the screen. With Pariwell, a photo of the oximeter on WhatsApp is read and added to the family's report, and a reading of 92% or lower alerts the family straight away.