This study builds on the findings from a previous literature review, which explored the relationship between Non-Suicidal Self-Injury (NSSI) and Self-Esteem. Resulting from this study was a need to further explore and clarify the concept of NSSI, and the aim of the current study is to gain such an understanding. Specifically, this pro-ject seeks to gain an in-depth understanding of the etiology and pathogenesis of NSSI as a phenomenon and thereby gain a better knowledge-foundation for a poten-tial clarification of NSSI as an official term. This has been sought through a qualita-tive research focus, which has considered a broad theoretical foundation on the sub-ject as well as the narratives of five informants with different histories of NSSI. The latter has been done through semi structured interviews and a following Thematic Analysis (TA). Through this it was concluded that several factors are crucial when seeking an understanding of the subject. First, NSSI is a heterogeneous phenomenon with many different underlying expressions and motivations. Second, several factors can be seen as precursors for the behavior such as the functions of NSSI, and the contextual inter- and intrapersonal elements of an individual’s life. Furthermore, the importance of personal narratives as well as the narratives of others has been seen when considering the general approach people have to NSSI. Lastly, it has been dis-cussed whether NSSI should be classified as a diagnosis within the DSM, and it was concluded that such an inclusion can be beneficial due to the ways of the western medical system, but a proper inclusion will require several clarifications to the stated terms in the research-diagnosis that is already present in the DSM-V.