In this review, an attempt was made to describe how non-insulin-dependent diabetes mellitus (NIDDM, type II diabetes) affects the life of the ill person. Patients are affected by and cope with this complex disease in different ways, depending on its severity and complications. Influences on well-being therefore also vary--from none to major deterioration. A substantial proportion of patients are primarily affected with fatigue, anxiety, and depression. Deteriorations in cognitive function have also been documented, although diverging evidence exists. Some negative social circumstances have also been noted. Social support, particularly specific support, appears to be helpful, although self-efficacy and health practices seem to be as important. Resistance to compliance with diabetes regimens together with reactions to the demands for increased levels of physical activity are often seen. Systematic focused studies examining how patients and significant others perceive the impact of the disease in retrospect are still awaited. There is a great need for more research on type II diabetes; broad prospective longitudinal follow-up studies monitoring natural disease progression, as well as examining the predictive significance of quality of life, would be welcome.