A 20-year-old nulliparous female college student sees the nurse because she has missed her last two menstrual periods. She reports she has not had sexual intercourse in one month. The nurse requests a pregnancy test, which is negative. Based on this client's history, which assessment is most important for the nurse to obtain?

A. Vaginal discharge, presence of genital warts, abdominal tenderness. While sexually transmitted infections (STIs) can cause irregular menstruation, this client has not had sexual intercourse in one month. The more likely causes of amenorrhea (missed periods) are hormonal or metabolic imbalances. B. Breast tenderness, tremors, high blood pressure. These symptoms could indicate premenstrual syndrome (PMS) or hyperthyroidism, but the primary concern in a young woman with missed periods is broader endocrine evaluation, including polycystic ovary syndrome (PCOS) and thyroid dysfunction. C. Urinary frequency, unsteady gait, dental enamel erosion. These symptoms suggest diabetes (urinary frequency), neurological issues (unsteady gait), or eating disorders (dental enamel erosion from vomiting in bulimia). While eating disorders can cause amenorrhea, a full endocrine and metabolic assessment is a more comprehensive first step. D. Body weight, hirsutism, thyroid enlargement. Polycystic ovary syndrome (PCOS) and thyroid dysfunction are common causes of amenorrhea in young women. PCOS can cause hirsutism (excess facial/body hair), weight changes, and irregular cycles, while thyroid enlargement (goiter) suggests hypothyroidism or hyperthyroidism, both of which can disrupt menstrual cycles.