The Smallest GSM module & microcontroller for Arduino

I’m looking for the smallest gsm module that I can program using arduino.
I’m building a fall detection system and I’m currently using a Bluetooth module to transfer the signal, now I wanna replace it with a SIM card so that it sends an SMS once the signal is produced.

I’m using adafruit pro trinket 3V as my micro controller. Also is there one smaller than the trinket and can be easily programmed with Arduino?

I’m looking to minmize the overall size of the system as much as I can , thus I’m looking for the smallest module sizes but are programmble with Arduino.

Can you please advice !

Thank you veey much