1. A diabetes self-care system, comprising: (a) a blood glucose meter; (b) a portable microprocessor-based unit signal coupled with the blood glucose meter such as to be capable of downloading blood glucose measurement data into the portable microprocessor-based unit; (c) said blood glucose data being used as input data for a program of instructions running on the portable microprocessor-based unit; and (d) said program of instructions including instructions to send a signal to inject insulin when blood glucose levels do not remain in a predetermined range.