Personality disorders result when personality traits become abnormal and cause significant social or occupational impairment or significant subjective distress. Eating disorders such as anorexia nervosa, bulimia nervosa and obesity are among the most challenging illnesses confronting the mental health profession. Nurses also come into contact with a variety of client concerns regarding sexual identity or activity. This chapter focuses on etiological factors, clinical features and clinical types of personality, sexual, psychosomatic, eating and sleep disorders. Using the nursing process approach the chapter describes the nursing care necessary for clients with such disorders.