Alerts

A call when the CGM loses signal

Overnight, a lost signal or a bad low rings your phone. An actual call, the kind that wakes you.

Overnight, the gap that matters is the one nobody hears: a sensor that drops out at 2 AM cannot warn anyone of a low at 4 AM. Dexcom's own FAQ says that while Follow shows No Data, it sends no notifications. Sugarmate calls on a low, and its no-data alert is a push notification.

"Over night our 18 year old son sometimes looses his CGM signal. He usually doesn't get up. If the last reading was in range 90 to 100 flat, do most parents let it ride over night or get up to change sensor?"

r/t1d_parents

That is the decision the call removes. You sleep; if the readings stop, the phone rings.

Glide at 2:47 AM showing 54 falling, with an incoming phone call banner from Glide Alarm at the top of the screen
2:47 AM. The call comes from Glide Alarm, a real phone number.

How it works

  1. Glide's server reads your CGM every minute, through Dexcom Share, LibreLinkUp or EasyFollow (Dexcom, Libre, Medtrum).
  2. You set the hours (for example 10 PM to 7 AM), a low threshold, and how long a gap counts as lost signal: 30 minutes by default, 15 at the least.
  3. Inside those hours, when the number crosses the threshold or no reading has arrived for that long, Glide places a phone call to the number you verified.
  4. While the condition holds, it calls again after the snooze you set (15 minutes by default), until the low clears or the readings come back.

The call is placed by the server, not by the app on your phone. The phone can be locked, in a Focus mode, or with Glide closed; the call still comes in, because with Emergency Bypass on, iPhone rings a call through Silent and Focus. The setup below turns that on.

Setup

  1. Settings → Alerts → Wake-up call. Enter your phone number and confirm the texted code. Numbers in the US, Canada and Europe work.
  2. Turn on the call, set the hours, the low threshold and Call on signal loss.
  3. Tap Add caller to Contacts, then in that contact turn on Emergency Bypass for calls. Without it, iPhone silences unknown callers overnight.
  4. Tap Send a test call. It checks the whole path, from the server to your ringer.
Signing out or deleting the app does not stop the calls. The call is a setting on Glide's server, so it works even when the app is gone. To stop it, turn off Wake-up call in Settings → Alerts.

Daytime: a banner

Outside the call hours, a lost signal is a Lock Screen banner after the same gap, on every phone that follows the profile, and the first reading after the gap arrives as Signal back with how long the feed was dark. Lows, fast rises and fast falls are banners too, with thresholds you set.

What it costs

The banners are free. The call is part of Glide Premium, $7.99 a month or $59.99 a year with a two-week free trial, and one subscription covers every phone on the profile. Details on the pricing section.

Glide is not a medical device. Keep your CGM app's own alarms on; Glide's alerts sit on top of them and do not replace them. A phone call depends on the phone network, the CGM maker's sharing service and Glide's server all working; status.glidebg.com shows the last of those.