What should you know about a Medica pulse oximeter?

A pulse oximeter uses light to estimate oxygen saturation and shows a pulse rate. It is a monitoring aid, not a complete assessment of breathing or circulation. Cold fingers, movement, nail products, poor circulation, and an imperfect fit can make the number unreliable. Skin pigmentation and some medical conditions can also affect interpretation. Look for a steady reading after resting and consider the person's breathing, colour, alertness, and overall condition rather than treating one isolated display as a diagnosis.

Warm your hand, remove anything covering the nail, and sit still with the hand relaxed below heart level. Place the probe as directed, wait for the display to settle, and record the reading with the time and symptoms. Repeat an unexpected result after checking fit and finger warmth. Do not change prescribed oxygen or other treatment based only on the device. A [Pulse Oximeter](/technology/pulse-oximeter/) guide explains the technology, while a [GP Consultation](/treatments/consultations-and-assessment/gp-consultation/) can put a persistent concern into context.

Seek emergency help for severe or rapidly worsening breathlessness, blue or grey lips, chest pain, fainting, new confusion, or inability to speak in full sentences. Seek prompt clinical advice for ongoing breathlessness, unusual sleepiness, or a reading that remains unexpectedly low after repeating it correctly. If symptoms are severe, do not wait for a device reading or delay emergency care while troubleshooting the monitor.

Ask what readings are expected for you, how to check the device's fit, when to repeat a measurement, and which symptoms require immediate help.