The numbers, finally explained
Vital-signs devices are just measuring tools with intimidating displays. Here's what each number means, when it matters, and when you can stop staring at it.
Measurement devices, one at a time
Each guide opens with the one-sentence version, then explains every reading in plain language.
Pulse Oximeters
The finger clip that reads your blood-oxygen (SpO2) and pulse. What's normal, what's not, and why cold hands fool it.
Decode the clip
Blood-Pressure Monitors
Systolic over diastolic, the right cuff position, and what counts as high. The top and bottom numbers, demystified.
Read the numbers
Glucometers
Blood-sugar testing without the panic. Strips, lancets, mg/dL vs mmol/L, and the readings that matter most.
Steady the sugarQuick monitor questions
Why is my pulse oximeter reading low?
Cold fingers, nail polish, movement and poor positioning all lower the reading falsely. Warm the hand, hold still, and re-check before worrying — but a persistently low SpO2 is always worth a call to your care team.
What's a 'normal' blood-pressure number?
Generally around 120/80, but 'normal for you' is what your clinician sets. The top number (systolic) is the squeeze; the bottom (diastolic) is the rest. We explain both in the guide.
Do I need to fast before a glucometer reading?
It depends what you're measuring — fasting vs after-meal. The glucometer guide walks through both, plus how to read the result without spiraling.
Not sure which monitor you've got?
Send us a photo or the model name. We'll point you to the right plain-English guide.