Gender medicine aims to improve the quality and accuracy of medical care by considering the influence of sex difference, gender difference, and life stage (LS) in the pathophysiology, diagnosis, treatment, and prevention of diseases of the reproductive system and common diseases of both sexes. In particular, sex and gender differences exist in the risk of developing and the way symptoms manifest in cerebral and cardiovascular diseases, endocrine disorders, autoimmune diseases, and psychiatric disorders. Cranial nerve disorders also require medical care that considers gender differences and LS. In one outpatient clinic specializing in women's health, 27% of patients previously diagnosed by their previous physicians with complaints were found to have underlying organic diseases. Women are more likely to have menstrual and menopausal symptoms that mask other diseases, and the diagnosis is more likely to be missed. The tendency of women to report symptoms from the periphery, due to their reluctance to speak clearly, also makes differential diagnosis difficult in the limited clinic time available. The accuracy of diagnosis, explanation of medical conditions, and quality improvement of disease prevention and treatment is expected to be achieved when medical providers have a "perspective and knowledge of sex and gender differences and LS."