Historically, blood glucose monitoring (BGM) device design has focused on the physiological aspects of diabetes, with less consideration for the psychological aspects of relating the measurement to one's experienced symptoms. In this pictorial, we explore how the subjective experience of blood glucose monitoring can be supported. We developed the BGM diary, a training system for existing BGM devices. The BGM diary involves a practice of guessing and measuring of blood glucose, followed by an annotation of felt symptoms to facilitate learning about experiences and symptoms. We unpack how blood glucose work could involve persons with diabetes in other ways in their care program through an elaboration on the design aspects of the BGM diary and reflections with a diabetes nurse.