will fall detection work with do not disturb on

Hello bubette47,

On iPhone:

1. Open Health
2. Tap your Apple ID Profile Picture (top right)
3. Tap Health Checklist
4. Scroll down and tap on Fall Detection
5. Make sure it's toggled on and is Always on

Use Fall Detection with Apple Watch - Apple Support

Yes, Fall Detection (and Crash Detection) will break through Focus modes. You will receive a message and a vibration notifying of the fall or crash and if you fail to respond, emergency services will be called automatically after roughly 20 seconds.

I hope this helps!

Fall Detection is only trigged after you make a hard enough fall to trigger it and don’t move after the fall. If you move after you fail (get up and walk around), Apple Watch assumes you’re okay.