Everyone experiences fatigue in daily life, but conscious awareness of fatigue differs considerably among individuals. A method for evaluating fatigue based on individual subjective symptoms was developed for labor hygiene in Japan, but in Europe and the United States, the scales employed have been widely developed mainly in the field of medical treatment. Adolescence and young adulthood are very important age stages in which physical fitness of young adults develops markedly and their lifestyle is determined. Adolescent and young adult lifestyles, and the causes and contents of their fatigue, differ considerably from those of laborers. Therefore, it is not appropriate to use fatigue scales developed for laborers to evaluate the fatigue of adolescents and young adults. Fatigue is closely related to health, physical fitness, and stress, and subjective fatigue symptoms can also be used as an important index for health evaluation. Considering the significance of today's fatigue evaluations for adolescents and young adults, it is indispensable to have simple and rational scales for subjective fatigue symptoms that evaluate fatigue appropriately. Study in this field has been progressing. Although there are various subjective fatigue scales, it is desirable to have detailed evaluations assuming 5 to 7 component factors. In this review, we discuss the definition of fatigue, the significance of fatigue evaluation based on subjective symptoms, and examine the history and component factors of fatigue. Through discussion, it is desirable to conduct more multifaceted research, focusing on the evaluation of subjective fatigue symptoms for adolescents and young adults.