Know your Oxygen Levels.Use them wisely.
Learn how to use a pulse oximeter at home, understand the numbers on the screen and recognise when a reading needs medical attention.
What does a pulse oximeter measure?
A fingertip pulse oximeter uses light to estimate your blood oxygen saturation and pulse rate. It provides a quick measurement without a blood sample.[1]
Oxygen saturation
An estimate of the percentage of haemoglobin carrying oxygen. This is the oxygen number.
Pulse rate
Your pulse in beats per minute. This is a separate measurement, not an oxygen percentage.
A reading can support a monitoring plan, but it cannot identify the cause of breathlessness or diagnose a condition on its own. A pulse oximeter also does not measure carbon dioxide.[7]
How to use a pulse oximeter at home
Read your device instructions first. Check that the batteries have enough power and use the finger position recommended by the manufacturer.[8]
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Rest before checking
Sit quietly for at least five minutes. Take a resting measurement unless your clinician has specifically asked you to check during activity.
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Prepare your hand
Warm cold hands. Remove nail polish or artificial nails from the finger you will use, where possible, and dry your hand.
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Position the clip
Insert your index or middle finger as directed. The sensor should fit comfortably. Do not put a fingertip-only device on your ear.
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Keep still
Switch it on and support your hand in the position your device instructions recommend. Avoid moving or talking while the signal settles.
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Wait for a steady result
Allow about a minute, or longer if needed, for a stable reading. Check the signal indicator if your model has one.
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Record both numbers
Write down SpO₂ and pulse rate, the date, time and how you feel. Identify the labels on the screen before recording.
Technique references: Africa CDC [2] and Open Critical Care [8].
What is a normal oxygen saturation reading?
For most healthy people, SpO₂ is usually 95–100%. Some people with lung conditions have a different prescribed range. Readings can also be lower at higher altitude.[3]
Use your clinician’s action plan first. The examples below concern new or unexpected resting readings in adults without an agreed lower target; they are not universal oxygen-treatment targets.
| SpO₂ reading | How to interpret it | What to do |
|---|---|---|
| 95–100% | Common in healthy adults. | Continue your agreed monitoring routine. Seek help if you feel seriously unwell despite the number. |
| 93–94% | A new, persistent low reading needs advice. | Repeat with correct technique. If it remains low, contact a clinician promptly, the same day. Escalate sooner if symptoms worsen. |
| 92% or below | A new or unexpected reading may need emergency assessment. | If you have no severe symptoms, recheck immediately. If still this low, seek emergency help. With severe symptoms, call immediately. |
| Your agreed rangeFor an individual treatment plan | Your clinician may set different targets. | Follow that plan and report a fall below your usual range or any deterioration. |
Typical range: MedlinePlus [3]. Escalation examples: NHS home-monitoring guidance [4], originally written for COVID-19 monitoring; individual clinical advice takes priority.
Do not wait for a low number to seek help.
Severe breathlessness, inability to finish short sentences at rest, chest pain, new confusion or collapse need urgent attention, whatever the display shows.[4][5]
South African emergency contacts: SA Government News Agency [6].
Why can a pulse oximeter reading be inaccurate?
Cold fingers, movement, poor circulation, nail coverings, a poorly fitting sensor and strong light can interfere with a reading. If the number is unstable, check these factors and repeat once you are settled.[5]
Some devices may overestimate oxygen saturation in people with darker skin. A seemingly normal result can therefore be falsely reassuring. Consider symptoms and changes from your usual readings, and seek medical advice if you are concerned.[5]
Do not add or subtract a fixed percentage to “correct” a result. Ask your clinician whether further assessment is needed. A clinical blood test may be used when a more direct measurement is necessary.[3][7]
Keep a simple record for your clinician
Check as often as your healthcare provider recommends. Record your symptoms alongside the numbers so changes can be discussed in context.[1]
| Date and time | SpO₂ / pulse | Symptoms and context |
|---|---|---|
| Your check | ___ % / ___ bpm | How you feel; resting or active; prescribed oxygen setting, if applicable. |
Take the device and your record to a consultation if results seem inconsistent. Clean and store the oximeter according to its manual, including any instructions for use by more than one person.[2]
What should you look for in a home pulse oximeter?
Choose a device intended for your needs, with a suitable sensor size, clear instructions and a readable display. Medical-purpose and general wellness devices are not necessarily evaluated in the same way.[1]
ChoiceMMed Medical Finger Pulse Oximeter
The MD300C29 displays SpO₂ and pulse rate on an OLED screen. OxyMed lists a case, lanyard, user manual and two AAA batteries with the unit.
- One-button operation
- OLED display
- Compact design
Check the product page for current price and availability. Ask OxyMed about product features and the supplied instructions; ask your healthcare provider about your target readings and treatment.
Pulse oximeter FAQs
Which finger should I use for a pulse oximeter?
Follow the device manual. The index or middle finger is commonly used. Make sure the sensor fits correctly and wait for a stable result.[2]
How long should I leave a pulse oximeter on?
For a spot check, allow about a minute or longer if the reading is unstable. Follow your device instructions; a spot check is different from continuous monitoring.[8]
Does a normal pulse oximeter reading mean I am well?
No. A reading cannot rule out illness. Seek medical help for serious or worsening symptoms even when the displayed oxygen level seems normal.[5]
Can a fingertip pulse oximeter diagnose sleep apnoea?
No. An ordinary spot reading cannot diagnose sleep apnoea. If it is suspected, your clinician can arrange appropriate assessment and sleep testing.[11]
Should I change my oxygen setting after a low reading?
Follow your clinician’s action plan. Do not independently change a prescribed flow rate or pulse setting to chase a number on the display.[9]
Why is my pulse oximeter not showing a reading?
Check the batteries, finger position and sensor fit. Warm cold hands and keep still. Follow the manual; seek medical care if you feel unwell.[8]
Choose your home monitoring equipment with confidence.
Speak to OxyMed about pulse oximeters and oxygen accessories, or view the product details online.
Sources and further reading
Sources checked on 11 November 2026. Home-monitoring advice must be adapted to your condition and your clinician’s instructions.
- FDA — Pulse Oximeter Basics. Display labels, monitoring and device limitations.
- Africa CDC — Community pulse oximeter guidance. Practical measurement technique; published for COVID-19 care.
- MedlinePlus — Pulse Oximetry. Typical ranges, altitude and clinical testing.
- Mersey Care NHS — Pulse oximeter guide. Home-monitoring escalation examples; COVID-19 context.
- Health Canada — Pulse oximeters for consumers. Skin pigmentation, accuracy and symptoms.
- SA Government News Agency — Emergency contacts. South African emergency and ambulance numbers.
- American Thoracic Society — Pulse Oximetry. Clinical context and what oximetry cannot measure.
- Open Critical Care — Operating a pulse oximeter. Device setup and signal checks.
- Cheshire and Wirral Partnership NHS — Oxygen safety. Follow the prescribed oxygen flow rate.
- OxyMed — ChoiceMMed Medical Finger Pulse Oximeter. Product details and included items.
- NHLBI, NIH — Sleep Apnea Diagnosis. Clinical assessment and sleep studies.
