Why your Apple Watch ECG says "poor recording" — and how to fix it
A "poor recording" message means your Apple Watch picked up too much movement or electrical noise during the 30-second reading to read a clean heart signal. The good news: it's almost always about how the reading was taken — not a problem with your heart. Here's why it happens and how to get a clean ECG every time.
The most common cause: damp contacts
In practice, the single most common reason for a poor recording is moisture at the contact points. The Apple Watch ECG depends on three dry contacts — the back of the watch against your wrist, the skin under the band, and the fingertip resting on the Digital Crown. If any of these is even slightly damp — from sweat, hand cream, water, or just washing your hands beforehand — the reading will usually come back poor.
This catches a lot of people out because it's the opposite of a clinical ECG machine, which uses gel electrodes where a little moisture actually improves contact. The Apple Watch uses dry electrodes, so the fix is reversed: make sure your wrist, your fingertip, and the back of the watch are all completely dry before you start. Wipe them down and try again.
Other reasons Apple Watch ECG recordings come out poor
The ECG app reads a tiny electrical signal between your wrist and the finger on the Digital Crown. Anything that disturbs that circuit shows up as noise. The usual culprits are:
- Movement — moving your arm, hand or fingers during the reading.
- An unsupported arm — holding your arm in the air instead of resting it.
- A loose (or overly tight) band — the back sensors lose steady skin contact.
- Damp skin or watch back (covered above) — the leading cause, from sweat, water or hand cream.
- Taking the reading on the charger or near other electronics.
- The wrong wrist or orientation set in the Watch app.
- A dirty back crystal or Digital Crown on the watch.
How to get a clean recording
- Dry everything first — wipe any sweat, water or lotion off your wrist, your fingertip and the back of the watch.
- Sit down and rest your forearm on a table or in your lap so it's fully supported.
- Make the band snug — you should be able to fit one finger under it, no looser.
- Take the watch off the charger and move away from other electronics.
- Hold a finger on the Digital Crown without pressing, and stay completely still.
- Breathe normally and don't talk for the full 30 seconds.
Still getting poor recordings?
- Check the wrist and orientation in the Watch app (Watch app → ECG) match how you actually wear it.
- Move the band up or down your wrist a little, or tighten it one notch.
- Try the other wrist to see if contact improves.
- Restart your Apple Watch and try again.
- If poor recordings persist across many attempts, have the watch checked.
Once your recordings are clean, get more from them. A good 30-second recording holds far more detail than Apple's app labels.
ECG+ re-analyses your clean Apple Watch recordings to surface what the standard app doesn't — PACs, PVCs, bigeminy, QT/QTc and more — so you can share clear evidence with your doctor.
Frequently asked questions
What does "poor recording" mean on Apple Watch ECG?
It means the watch picked up too much movement or electrical noise during the 30-second reading to read a clean heart signal. It is almost always about how the reading was taken, not a problem with your heart.
How do I stop getting poor recordings on Apple Watch ECG?
Rest your forearm on a table, make the band snug, sit still and don't talk for the full 30 seconds, take the watch off the charger, and make sure your skin and the sensors are clean. Moistening very dry skin can also help.
Does moisture or sweat affect Apple Watch ECG?
Yes — and it's often the main culprit. Unlike a clinical ECG that uses wet gel electrodes, the Apple Watch uses dry electrodes, so a damp wrist, fingertip or watch back tends to produce a poor recording. Drying the contact points completely before you start usually fixes it.