How to Use a Pulse Oximeter: SpO2, Accuracy, and When to Worry (Australia)

A pulse oximeter is a small clip-on device that measures two things: your blood oxygen saturation (SpO2) and your pulse rate. It does this non-invasively in seconds, using infrared light transmitted through your fingertip.

What Does SpO2 Mean?

SpO2 stands for peripheral capillary oxygen saturation — the percentage of haemoglobin in your blood that is carrying oxygen. In a healthy adult at sea level, normal SpO2 is 95–100%.

Below 95% is generally considered below normal. Below 92% typically warrants clinical attention. Below 88% is commonly the threshold for supplemental oxygen therapy in patients with chronic lung disease. For patients already on home oxygen therapy, see our Yuwell oxygen concentrator guide for information on how to monitor therapy effectiveness.

Who Benefits from a Home Pulse Oximeter?

• COPD and emphysema patients — see our COPD equipment guide for how oximeters fit into a complete home respiratory monitoring setup
• Asthma patients — a falling SpO2 during an attack is a warning sign of deteriorating severity
• Sleep apnoea patients — see our CPAP vs BiPAP guide for context on how SpO2 monitoring relates to PAP therapy
• Post-COVID recovery — tracking oxygenation during exertion
• High-altitude activities
• Endurance athletes
• Carers of elderly or unwell family members

How to Get an Accurate Reading

1. Warm your hands first. Cold fingers reduce peripheral circulation and cause falsely low SpO2 readings.
2. Remove nail polish. Dark or opaque colours absorb infrared light and interfere with the reading.
3. Sit still for at least 30 seconds. Motion artefact is one of the most common causes of erratic readings.
4. Shield from bright light.
5. Use the correct finger. The middle finger of either hand typically gives most consistent readings.

When to Seek Medical Attention

• SpO2 drops below 92% and stays there on repeated readings
• SpO2 is below 88% at any point
• You're experiencing breathlessness, chest pain, or confusion alongside a low reading

For patients also monitoring blood pressure, see our guide on how to take an accurate blood pressure reading at home. The two together give a more complete picture of cardiovascular and respiratory health.

Our Pulse Oximeter Range

• YX300 — $49.95: Clinical-grade with strong anti-interference performance
• YX301 — $49.95: Standard home and clinical use with auto-rotating display
• YX302 — $49.95: Same specs as YX301, different case design

All three are TGA-approved and include a lanyard and storage pouch.

Shop TGA-approved pulse oximeters →