The portfolio thesis has three parts:Part one is a systematic literature review reviewing the literature on the relationship between parenting style and diabetes management in children and young people with type 1 diabetes. Seven papers were systematically reviewed and the findings and clinical implications are discussed.Part two is an empirical paper, which explores adolescents with type 1 diabetes perceptions of control. Six adolescents who perceived themselves to have low personal and/or treatment control were interviewed about their experiences. The interviews were analysed using Interpretative Phenomenological Analysis. The findings of the study are discussed along with the clinical implications of the study and areas of future research.Part three comprises the appendices, which compliment parts one and two of the portfolio. The appendices also includes a reflective statemen