Cervix: The narrow, lower part of the uterus that connects to the vagina.
Dysmenorrhea: The medical term for painful periods.
Endometriosis: A condition where uterine-lining-like tissue grows outside the uterus.
Estrogen: A key hormone that helps build the uterine lining and drives puberty changes.
FSH: Follicle-stimulating hormone; signals the ovaries to prepare an egg.
Fibroid: A non-cancerous growth in or around the uterus.
LH: Luteinizing hormone; triggers the release of an egg (ovulation).
Menarche: The medical term for a person's first period.
Menstrual cycle: The repeating, roughly monthly process the body goes through to prepare for a possible pregnancy.
Ovulation: The release of a mature egg from an ovary, usually near the midpoint of the cycle.
PCOS: Polycystic Ovary Syndrome; a hormonal condition affecting ovulation and the cycle.
PMDD: Premenstrual Dysphoric Disorder; a severe form of PMS involving intense mood symptoms.
PMS: Premenstrual Syndrome; physical and emotional symptoms in the days before a period.
Progesterone: A hormone that helps maintain the uterine lining after ovulation.
Puberty: The years when a child's body gradually develops into an adult body.
Uterus: The pear-shaped, muscular organ where the lining builds up and sheds each cycle.
Vulva: The external genital area, including the labia and clitoris.