Active Hormone Pill: An oral contraceptive pill that contains estrogen, progesterone, or both.
Add–Back Therapy: Hormonal therapy prescribed to help females with the side effects of a class of medicine called GnRH agonists.
Bladder: The organ that collects and stores urine.
Bone Density: How solid and strong your bones are.
Break-through Bleeding: Light vaginal bleeding or spotting that can happen during the first month on oral contraceptive pills (OCP’s) or when switching to another kind of OCP, or when a pill is missed or late. Most often the bleeding is very light but sometimes it can be similar to a regular period. Break-through bleeding refers to bleeding when you do not expect it, such as when you are taking hormone pills and not inactive pills.
Chronic: A condition that continues for a long time.
Dysmenorrhea: Pain with periods, menstrual cramps.
Endometrial Cells: Cells from the lining of the uterus.
Endometrial Lesions (Implants): Tissue from the lining of the uterus that sticks and grows outside of its normal location.
Endometrial Tissue: Tissue from the lining of the uterus.
Endometriosis: A condition that occurs when tissue similar to the lining of the uterus is found outside its normal location.
Estrogen: A female sex hormone.
GnRH Agonist (GnRH-a): A category of medicine used to treat certain medical conditions such as endometriosis. This medicine works by lowering the body’s level of the hormone estrogen.
Gynecologist: A doctor with additional medical and surgical training in the area of female reproductive health.
Hormone: A chemical messenger that is released by an organ or gland and then sent through the bloodstream to another part of the body.
Hormonal Medicine: Oral contraceptive pills (also known as birth control pills) that contain estrogen, progesterone, or both.
Immune System: The system in your body that protects against disease, infection, and foreign substances.
Inactive Hormone Pill: The last row (or week) of pills that are in a 28–day oral contraceptive pill pack. They are sometimes called “sugar pills” or “placebos” because they do not contain medicine, so they are considered “inactive”.
Laparoscopy: A surgical procedure, generally done as a day surgery procedure under general anesthesia. A small incision is made near the navel, and a lighted, thin tube is inserted to view the pelvic organs.
Menstruation: The release of blood from the uterus.
Menstrual Cramps: Pain in the lower abdomen (belly) during a period.
Nausea: Feeling like you are going to throw up.
Omega–3 Fatty Acids: Omega–3 fat is a “heart healthy” type of fat that your body needs. Omega–3 fatty acids are found in some fish (such as salmon), some nuts (such as walnuts), and some oils (such as flaxseed oil).
Organic Foods: Organic produce is grown without the use of pesticides, synthetic fertilizers, sewage sludge, genetically modified organisms, or ionizing radiation. Animals that produce meat, poultry, eggs, and dairy products do not take antibiotics or growth hormones.
Ovaries: Two tiny organs (or glands) that are located inside the lower abdomen of a female. The ovaries make the female hormones estrogen and progesterone.
Pelvic Ultrasound: A test that uses sound waves to make a picture of the reproductive organs; ovaries, fallopian tubes, uterus, cervix, and bladder.
Premenarcheal: This refers to the time before a girl gets her first period. “Pre” means before and “menarcheal” means menstrual period.
Trans Fat: Trans fat is a “heart unhealthy” type of fat. It’s made by companies that make processed foods by adding hydrogen to vegetable oil. Foods with trans fat will have the words “partially hydrogenated oil” in the ingredient list. Trans fat can be found in some margarines, fast foods, fried foods, and baked goods.
Ultrasound: A way to take pictures inside of body parts. Pictures taken by ultrasound are similar to x–ray photographs. However, when ultrasound is used, the images are made with sound waves instead of x–rays.
Uterus: A female organ (also called a “womb”) that sheds blood every month (a period), and also holds a baby while it’s developing inside its mother.
Our health guides are developed through a systematic, rigorous process to ensure accuracy, reliability, and trustworthiness. Written and reviewed by experienced healthcare clinicians from Boston Children's Hospital, a Harvard Medical School teaching hospital and consistently ranked as a top hospital by Newsweek and U.S. News & World Report, these guides combine clinical expertise, specialized knowledge, and evidence-based medicine. We also incorporate research and best practices from authoritative sources such as the CDC, NIH, PubMed, top medical journals, and UpToDate.com. Clinical specialists and subject matter experts review and edit each guide, reinforcing our commitment to high-quality, factual, scientifically accurate health information for young people.