The document discusses infertility, which is defined as the inability to have biological children. Major causes of female infertility include endometriosis, ovulation problems, poor egg quality, polycystic ovary syndrome, and blocked fallopian tubes. Endometriosis involves endometrial tissue growing outside the uterus, causing painful periods and irregular bleeding. Ovulation problems prevent egg release, while poor egg quality involves damaged or abnormal eggs. Polycystic ovary syndrome features ovarian cysts and hormonal issues that inhibit ovulation. Blocked fallopian tubes prevent egg and sperm from meeting. Male infertility can be caused by blocked tubes or low/poor quality sperm. Unexplained infertility means the cause cannot be determined, while