The onset of dementia involves various conditions, such as genes and sex hormones, and its precise mechanism has not been clarified. However, it has been known among medical workers that there are differences between men and women, or sex differences, in dementia. The incidence of Alzheimer’s disease in women is about twice that in men, and they account for a larger number of patients than men. Nursing care workers have come to recognize diversity in sex, and be more aware of considerations to sexual minorities.