Electrical Health Products

A pulse oximeter is a small clip-on device, usually worn on a fingertip, that measures blood oxygen saturation (SpO2) and pulse rate at the same time. It works by shining light through the skin and calculating how much is absorbed by oxygenated versus deoxygenated blood. It gives a quick, non-invasive way to check how well oxygen is being carried around the body, and is commonly used by people monitoring a respiratory condition or simply wanting a general health check at home.

The top reading is SpO2, your blood oxygen saturation shown as a percentage, and the bottom reading is pulse rate in beats per minute. For most healthy adults, a normal SpO2 reading sits between 94% and 98%, though this can vary slightly by device and individual. A reading that is consistently below 92%, or accompanied by breathlessness, should be discussed with a GP or NHS 111, as a pulse oximeter is a monitoring tool and not a substitute for professional medical assessment.

The index or middle finger on either hand generally gives the most reliable reading, as these tend to have better circulation than the smaller fingers. For accuracy, remove nail polish or false nails beforehand, keep hands warm, and sit still for a few seconds while the reading settles. Cold fingers or poor circulation can affect the accuracy of any fingertip pulse oximeter.

For the most accurate reading, sit quietly for five minutes beforehand and avoid caffeine, exercise and smoking in the 30 minutes prior. Sit with your back supported and feet flat on the floor, and rest your arm on a table so the cuff sits roughly level with your heart. Wrap the cuff snugly around a bare upper arm or wrist, depending on your blood pressure monitor, stay still and avoid talking during measurement, and take two or three readings a minute apart to get a reliable average.

A blood pressure reading gives two numbers: systolic pressure (the higher number, measuring pressure as the heart beats) over diastolic pressure (the lower number, measuring pressure as the heart rests between beats). A normal reading for most adults is generally considered to be around 120/80mmHg, while a reading consistently at or above 140/90mmHg is classed as high. A single high reading is not a diagnosis. If your readings are regularly outside the normal range, speak to a GP or pharmacist.

Home blood pressure monitors typically range from around £20 for a basic wrist or upper arm digital monitor to £50 or more for models with additional features such as irregular heartbeat detection. Our blood pressure monitor starts from £19.99, giving accurate, portable monitoring without needing to visit a clinic.

Most digital home blood pressure monitors are factory calibrated and do not need routine calibration by the user. To check accuracy, take a reading at home shortly before or after a reading taken by a GP or pharmacist and compare the two figures. A difference of more than 5mmHg either way may indicate the device needs checking, in which case contact the manufacturer, as most offer a calibration or replacement service.

Clean the tip of your digital thermometer with an alcohol wipe before and after use, then place it under the tongue, in the armpit, or as directed by the manufacturer. Keep the mouth closed or arm still until the thermometer beeps, usually within 60 seconds, then read the display. Oral readings tend to run slightly higher than underarm readings, so use the same method consistently when tracking changes over time.

An infrared thermometer measures the infrared energy naturally radiated by the skin, typically at the forehead or temple, and converts this into a temperature reading without touching the skin. Because there's no direct contact, it's quick and hygienic, taking a reading in around one second, which is useful when checking multiple people or for anyone who finds oral thermometers uncomfortable. For consistent results, use it at a similar distance from the skin each time and avoid taking a reading in direct sunlight, draughts or straight after exercise.

Digital weighing scales are generally accurate to within a small margin, but readings can be thrown off by the surface they're placed on (a hard, flat floor gives the most reliable result), low battery, or even the time of day you weigh yourself. For the most consistent tracking over time, weigh yourself at the same time of day, on the same surface, and in similar clothing.