Breast Conditions Some breast changes or conditions are related to a young woman's menstrual cycle, but others may occur at any time. Most breast conditions are benign. Amenorrhea in Teens Amenorrhea is a menstrual condition in which a woman's menstrual periods are absent for more than three monthly cycles. Pregnancy is one possible cause of amenorrhea. Dysmenorrhea in Adolescents Dysmenorrhea is a menstrual condition marked by severe and frequent menstrual cramps and pain. Dysmenorrhea can be either lifelong or caused by another medical condition. Vulvitis in Teens Vulvitis is an inflammation of the vulva, the soft folds of skin outside the vagina. It is a symptom of a host of diseases, infections, injuries, and allergies. Vaginitis in Adolescents Vaginitis is a common problem for women of all ages. Bacteria, yeast, viruses, and chemicals in creams or sprays can cause it. Sexually Transmitted Diseases in Adolescents STDs are among the most common infectious diseases in this country—the United States has the highest rates of STDs in the industrialized world. Safer Sex Guidelines for Adolescents The only safe sex is no sex, most health care providers say. But certain precautions and safe behaviors can minimize a person's risk of contracting a sexually transmitted disease. Premenstrual Syndrome (PMS) Most females experience some unpleasant or uncomfortable symptoms during their menstrual cycle. The type and intensity of symptoms vary.