If you’ve been given a pulse oximeter, you may be asked to check your oxygen levels once or twice a day. The device clips over your finger. It does not hurt and only takes a minute to check your level. You can also purchase a pulse oximeter from a pharmacy over the phone or online, and have it delivered to your home. Some smartphones and smartwatches have a pulse oximeter function, however these are not accurate and should not be used. Pulse oximeter An oximeter clips onto your finger. If you are looking after a child with COVID-19 and are asked to monitor oxygen levels, you might require a pulse oximeter specially designed for children. Your GP or nurse will discuss this with you. When testing your oxygen: Remove any nail polish or false nails. These can interfere with the device. Wash your hands with warm water and thoroughly dry them. The device works best when your hands are warm. Sit in an upright position. Give your fingers a wiggle and rub them to get the blood flowing. Attach the clip to one of your fingers so that the tip of your finger is touching the end of the device. The palm of your hand should be pointing down, and the screen of the pulse oximeter should be pointing up so you can read it. Keep your hand and fingers still. Breathe normally and restfully. After waiting for 1 minute, record the number next to the SpO2 symbol. Your oxygen level should be 95% or higher. If it’s lower than this, then it could be a sign you need more frequent check-ups with your GP or nurse, or that it is safer for you to be in hospital. If you are not getting a reading, or if the reading is under 95%, give your fingers a wiggle, take a few breaths and try the device on a different finger. If it is still low, contact your GP or nurse. Pulse oximeters may over or under-estimate oxygen saturation. The accuracy of the measurement can be affected by many factors, including skin pigmentation, correct fitting of the device, peripheral blood flow, nail coatings, tattoos and dyes, and maintenance and cleaning of the devices. It’s important to remember that pulse oximeters should only be one part of an overall treatment plan between you and your GP.