Home vitals: which numbers are worth tracking
Wearables and home devices will happily generate forty metrics a day. Medicine runs on about six. Here's the candid sort: which home measurements carry real clinical signal, what normal looks like, and which dashboard numbers are entertainment.
The measurements that earn their place
| Measurement | Typical adult range | Who should track it |
|---|---|---|
| Blood pressure | Below 120/80 mmHg is normal; sustained 130/80+ is hypertension territory | Anyone with elevated readings, on BP medication, or over ~40 — see the full BP guide |
| Resting heart rate | Roughly 60–100 bpm; athletes run lower | Everyone with a pulse and thirty seconds; morning, before coffee, is the clean reading |
| Weight | Trend matters, not the day-to-day ±1–2 kg of water | Weekly for most; daily for heart failure, where 2–3 lb overnight or ~5 lb in a week is a call-your-clinician signal, not a diet observation |
| Oxygen saturation (SpO2) | 95–100% for most healthy adults | Respiratory illness, lung conditions; occasional spot-checks otherwise. Below ~92% while sick warrants a call; readings in the 80s warrant urgent care |
| Temperature | ~97–99.5°F (36.1–37.5°C); fever ≥100.4°F (38°C) | When ill. Trend and response to fluids/rest matter more than a one-time 99.2 |
| Glucose | Fasting ~70–99 mg/dL for non-diabetics | Diabetes and prediabetes, per your care plan — this one's between you and your clinician |
Cheap, boring, validated devices beat premium gadgets for all of these: an upper-arm BP cuff, a fingertip pulse oximeter, a bathroom scale, a basic thermometer. The measurement ritual (rested, seated, consistent time of day) does more for data quality than any amount of hardware.
What you can mostly ignore
Sleep scores, readiness scores, "stress" indices, and calorie burn estimates are proprietary blends with no reference ranges and poor cross-device agreement — fine as gentle nudges, useless as medical data. The honest test for any metric: would a clinician change anything based on it? For the six above, routinely yes. For a readiness score, no.
One exception worth naming: irregular-rhythm notifications from wrist devices have a real track record of surfacing atrial fibrillation. Treat the alert as a prompt to get a proper ECG — not as a diagnosis, and not as reassurance when absent.
Make the numbers add up to something
A reading you glance at and forget is a heartbeat's worth of information; the same reading in a series is a trend line — and trends are where home vitals pay off. The failure mode is fragmentation: BP in the cuff's app, weight in the scale's app, SpO2 on a sticky note. Five years later, when a clinician asks "how long has this been drifting?", the answer is scattered across four companies' clouds, two of which no longer exist.
The two-question filter before adding any metric
1. Is there a decision attached? Daily weights in heart failure trigger a med adjustment; that's a decision. 2. Will you still measure it in three months? A short list you sustain beats a dashboard you abandon. Blood pressure twice a week for years is worth more than everything a smartwatch collected in a January of enthusiasm.