Why vital signs matter for carers
You don't need to be a nurse to keep an eye on your loved one's vital signs. Simple home monitors — many of which cost less than £30 — can give you early warning signs that something is changing, often before symptoms become obvious.
The key isn't memorising textbook ranges. It's understanding what's normal for your loved one, so you can spot when something shifts.
Blood pressure
Blood pressure is recorded as two numbers: systolic (the top number, when the heart contracts) and diastolic (the bottom number, when the heart relaxes).
- Ideal: around 120/80 mmHg
- High: consistently above 140/90 — increases risk of stroke and heart attack
- Low: below 90/60 — can cause dizziness, fainting, and falls
In older adults, blood pressure often varies throughout the day and can drop significantly after eating or standing up (called postural hypotension). If your loved one feels dizzy when they stand, measure their blood pressure sitting and then standing — the difference matters.
When to act: A single high or low reading isn't usually an emergency. But if readings are consistently outside your loved one's normal range, or if they're experiencing symptoms (headache, dizziness, chest pain), contact the GP.
Heart rate (pulse)
A normal resting heart rate for adults is between 60 and 100 beats per minute. Many older adults naturally sit at the lower end.
- Too fast (tachycardia): over 100 at rest — could indicate infection, dehydration, pain, or heart problems
- Too slow (bradycardia): under 60 — sometimes normal (especially if on beta-blockers), but can cause fatigue and dizziness
- Irregular: a pulse that's noticeably uneven may suggest atrial fibrillation (AF), which needs medical attention
When to act: If the heart rate is persistently above 120 or below 50 with symptoms, seek medical advice promptly. An irregular pulse should always be checked by a doctor.
Temperature
Normal body temperature is around 36.1–37.2°C (97–99°F). In older adults, temperature regulation is less efficient, so a "normal" temperature may be slightly lower than in younger people.
- Fever: above 37.5°C — often indicates infection
- Hypothermia risk: below 35°C — a real danger for elderly people, especially in winter
Importantly, some older adults don't develop a fever even when they have a serious infection. If your loved one seems unwell but their temperature is normal, don't rule out infection — look at the full picture.
When to act: A temperature above 38°C or below 35°C warrants a call to the GP or 111. If accompanied by confusion, rapid breathing, or drowsiness, call 999.
Oxygen saturation (SpO2)
A pulse oximeter — the small clip that goes on the finger — measures how much oxygen is in the blood.
- Normal: 95–100%
- Concerning: 92–94% — contact the GP
- Emergency: below 92% — call 999
Some people with chronic lung conditions may have a lower baseline. Ask the GP what's normal for your loved one and write it down.
Keeping a log
The real value of tracking vital signs isn't in any single reading — it's in the trend. A gradual decline in blood pressure over weeks, or a slowly rising resting heart rate, tells a story that a single snapshot can't.
Log readings consistently — same time of day, same conditions — and share them with the care circle. When you next see the GP, bring the log. Doctors make better decisions with better data.