HealthInfo Canterbury
How to use a pulse oximeter for adults
A pulse oximeter is a small, painless device that clips on your finger and uses light beams in a sensor to estimate the amount of oxygen in your blood without taking a blood sample. This helps to track and assess how well your lungs are working.
A pulse oximeter can be used to help monitor a range of conditions in hospital or at home, including COVID-19.
COVID-19 is a viral infection. Most people have relatively mild symptoms, and they usually get better over two to three weeks. But some people have very serious symptoms, which can get worse quickly.
Recording your symptoms in a COVID-19 health and symptom diary can help you and your COVID-19 healthcare team track any changes in your symptoms and breathing.
A pulse oximeter measures two things.
- Pulse – this is a measure of how fast your heart is beating. Your pulse is measured in beats per minute (bpm). On your device, this number may show as bpm or PRbpm (pulse rate/beats per minute).
- Oxygen saturation level – this is a measure of how much oxygen is in your blood. Oxygen saturation is measured as a percentage (scored out of 100). On your device, this number may show as SpO2% (saturation percentage of oxygen).
Important
Don't solely rely on a pulse oximeter to assess your health condition or oxygen level.
Other signs of low oxygen levels are:
- bluish colouring in your face, lips or nails
- shortness of breath, difficulty breathing or a cough that gets worse
- restlessness and discomfort
- chest pain or tightness
- fast or racing pulse rate.
If you experience any of these symptoms or your symptoms suddenly become worse, call 111 for an ambulance.
If you have any concerns or questions, contact your COVID-19 healthcare team.
Using a pulse oximeter
There are different brands of these devices – please read the manufacturer's instructions.
The following is a general guide. Ask your COVID-19 healthcare team if you have any questions.
Preparing
- Wash your hands and remove any nail polish or false nails. This allows the light beams in the sensor to measure through your fingernail.
- Make sure you've been resting for at least five minutes before taking the reading.
- If your hands are cold, warm them by rubbing them together.
- Rest your arm and hand and keep them still while taking your reading.
- Your hand should be at waist level. For example, resting on a table or chair arm.
Taking your reading
- Switch the pulse oximeter on and the display will light up.
- Squeeze it to open it and insert your finger until your fingertip touches the end.
- It works best on the middle or index finger of either hand.
- Keep your hand still and wait for one to two minutes until your pulse (bpm or PRbpm) is steady and your oxygen saturation (SpO2%) number hasn't changed for five seconds or more.
- If your numbers aren't steady, try a different finger.
Recording your numbers
- You should record your oxygen saturation number (SpO2%) and pulse rate number (bpm or PRbpm) to track any changes. You can print and fill in this COVID-19 health and symptom diary.
- Your pulse rate and oxygen saturation numbers are easy to mix up. Be careful to record these correctly.
- Measure and record your pulse rate and oxygen saturation three times a day at about the same times each day.
- Your health diary is crucial to track any changes so your COVID-19 healthcare team can monitor you safely at home.
- You should take extra measurements if you feel a change in your health.
- To clean your device, check the manufacturer’s instructions.
Pulse oximeter numbers
Your COVID-19 healthcare team will give you details on appropriate oxygen saturation levels for your specific medical condition. The following is a guide for adults with no previous lung conditions.
Oxygen saturation |
Pulse rate |
Action |
|---|---|---|
95 to 99 |
50 to 99 |
Acceptable. |
92 to 94 |
100 to 119 |
Seek advice from your COVID-19 healthcare team. |
Below 92 |
120 or higher |
Call 111 for urgent medical care. |
If your oxygen saturation number drops by 3% or more from your first reading, contact your COVID-19 healthcare team.
HealthInfo recommends the following pages
- British Asthma and Lung UK – Pulse oximetry
Information about pulse oximetry and oxygen saturation.
Content shared between HealthInfo Canterbury, KidsHealth and Healthify He Puna Wairoa as part of a National Health Content Hub collaborative. Last reviewed February 2022.
See also:
Review key: HICOV-710714
