This paper describes the psychological consequences of physical illness or defect and examines their relationship to the concept of deficit which, in turn, has often been contrasted with psychological conflict. The psychological consequences of physical illness or defect differ in response to various parameters, particularly whether the defect is small, moderate, or severe. Typically, each has its special characteristics, which are considered here in detail. The author underscores that the concept of deficit, which refers to deficiencies in the structuralization of the personality, remains of uncertain scope and definition, despite its frequent use in recent years, mainly in the context of self psychology. Most important is to clarify the relationship between deficit and conflict. The paper explores the terms "defect," "deficiency," "deficit," and "sense of defectiveness"--all of which have similar but different meanings. A further complication arises because these terms have been used sometimes descriptively and atheoretically or as metapsychological concepts embedded in various aspects of psychoanalytic theory.