1. What is the difference between primary and secondary dysmenorrhea? Primary dysmenorrhea is menstrual pain that occurs without any underlying pelvic pathology, while secondary dysmenorrhea is menstrual pain that is caused by an identifiable pelvic disorder, such as endometriosis, fibroids, or pelvic inflammatory disease. 2. What are the common causes and treatments of abnormal uterine bleeding (AUB)? AUB is bleeding from the uterus that is abnormal in frequency, duration, amount, or timing. The common causes of AUB include hormonal imbalances, structural abnormalities, infections, medications, systemic diseases, and malignancies. The treatments of AUB depend on the underlying cause and the patient's preferences, but may include hormonal therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), tranexamic acid, uterine artery embolization, endometrial ablation, hysteroscopy, or hysterectomy. 3. What are the risk factors and symptoms of ovarian cancer? Ovarian cancer is a malignant tumor that originates from the ovaries. The risk factors for ovarian cancer include age, family history, genetic mutations (such as BRCA1 or BRCA2), personal history of breast or endometrial cancer, nulliparity, infertility, early menarche, late menopause, hormone replacement therapy, and obesity. The symptoms of ovarian cancer are often vague and nonspecific, such as abdominal bloating, pelvic pain, urinary frequency or urgency, changes in bowel habits, weight loss, fatigue, or postmenopausal bleeding. 4. What are the indications and contraindications of combined oral contraceptives (COCs)? COCs are pills that contain synthetic estrogen and progestin hormones that prevent ovulation and alter the cervical mucus and endometrium to prevent pregnancy. The indications of COCs include contraception, menstrual regulation, dysmenorrhea relief, acne treatment, premenstrual syndrome (PMS) management, endometriosis suppression, polycystic ovary syndrome (PCOS) improvement, and reduction of ovarian and endometrial cancer risk. The contraindications of COCs include pregnancy, breastfeeding (within 6 weeks postpartum), history of thromboembolic events (such as stroke or pulmonary embolism), cardiovascular disease (such as myocardial infarction or angina), uncontrolled hypertension (>160/100 mmHg), migraine with aura (>35 years old), liver disease (such as cirrhosis or hepatocellular carcinoma), breast cancer (current or past), undiagnosed abnormal uterine bleeding, or hypersensitivity to any component of the pill. 5. What are the advantages and disadvantages of intrauterine devices (IUDs)? IUDs are small T-shaped devices that are inserted into the uterus by a health care provider to prevent pregnancy. There are two types of IUDs: copper IUDs and hormonal IUDs. Copper IUDs work by releasing copper ions that impair sperm motility and viability and induce a sterile inflammatory response in the endometrium. Hormonal IUDs work by releasing progestin hormones that thicken the cervical mucus and thin the endometrium to inhibit sperm penetration and implantation. The advantages of IUDs include high efficacy (>99%), long duration (3-10 years depending on the type), reversibility (fertility returns quickly after removal), convenience (no need for daily or coital use), cost-effectiveness (low long-term cost), and non-interference with lactation or sexual function. The disadvantages of IUDs include insertion-related pain and bleeding, expulsion