What should you know about an online pulse oximeter?

A fingertip pulse oximeter uses light to estimate oxygen saturation in the blood and displays a pulse rate. It does not diagnose the reason for breathlessness, chest discomfort or a fast pulse. Cold fingers, movement, nail products, poor circulation and an awkward fit can make a reading unreliable. Skin pigmentation and device quality can also affect performance. One unexpected number should be checked rather than interpreted in isolation, especially if you feel unwell.

Rest quietly, warm your hand and remove nail polish if practical. Place the device securely on a finger, keep your hand still and wait for the display to settle. Record the reading, pulse and your symptoms, then repeat once if the result seems inconsistent. Follow the device instructions and do not use it to delay medical help. A GP consultation can put home readings into context and assess your breathing, circulation and medical history.

Call emergency services for severe breathlessness, blue or grey lips, fainting, new confusion, severe chest pain or inability to speak in full sentences. Seek prompt medical advice for a persistently concerning reading, worsening breathing, or a reading that does not fit how you feel. People with chronic lung or heart conditions should follow their personalised action plan.

Is this device suitable for my situation? What readings or symptoms should trigger a call? Could my medicines or lung condition affect the result, and how should I record readings for review?