There is a lot of talk about measuring blood oxygen saturation at home using pulse oximeters to give early warning of COVID-19 symptoms and to allow the early presentation at hospital. If testing at home, you need to know what is normal and ideally the testing should be part of a management plan and under the supervision of a healthcare professional.

According to the British Lung Foundation, the normal blood oxygen saturation level for someone who’s healthy will be around 95–100%. If the oxygen level is below this, it can be an indicator that there is a lung problem.

Be wary of devices sold online at inflated prices, approved medical devices must display a CE mark and be certificated. To use a pulse oximeter correctly and obtain accurate results, the meter must be held steady in place for 30 seconds to allow the oximeter to calibrate. if there is movement, or poor placement or the finger is in the device for too short a duration, readings may be inaccurate. If there are underlying medical conditions or is anything to block the light from the device getting to your blood, such as false nails or gel nail polish the reading may be affected.