Abnormal uterine bleeding is a common clinical problem in adolescence but also a potentially difficult condition to treat. Furthermore, most diagnostic criteria and treatment algorithms were optimized for adults and not validated for adolescent population. Abnormal uterine bleeding may be associated with many conditions, including pregnancy, endocrine disorders, chronic diseases and congenital conditions. Using the menstrual cycle as an additional vital sign adds a powerful tool for the isolation of pathological conditions via the assessment of normal development. It is important for clinicians to have an understanding of bleeding patterns of adolescents, the ability to distinguish normal menstruation from abnormal one, and the skill to evaluate the young female patient appropriately. Routine evaluation should include a careful history, physical examination as indicated and permitted, and laboratory studies including a pregnancy test and a complete blood cell count. Quantifying the level of anemia and degree of bleeding along with managing expectations will provide basis for a more successful treatment plan that can almost always avoid surgical methods.