Whereas normative stressors are usually dealt with without manifest abnormalities, the first appearance of a serious incurable chronic illness could become a nonnormative stressor that possibly overtaxes an adolescents' coping abilities. This chapter provides a brief overview of the current state of research on coping with illness in adolescence. Then, the focus shifts to how the afflicted adolescent makes use of assistance provided by social and medical support systems, in which manner an adolescent's further development is affected by the illness, and what kinds of long-term consequences are involved. In particular, the effect of the chronic illness on psychological health is analyzed. Research findings obtained in the Bonn longitudinal study of diabetic adolescents and their families (Seiffge-Krenke et al., 1996) are presented to illustrate these salient issues.