What type of diabetes do I have?

[Jo88]

I have recently been diagnosed as type 1 but was wondering what the medical name for this is? I have an application form for a prescription charge exemption card, but am not sure whether to tick 'diabetes mellitus' or 'diabetes insipidus'

Any help would be much appreciated

 

[AMBrennan]

The former (diabetes mellitus).

diabetes insipidus is something entirely different.