Endometriosis: A Glossary of Terms

Boost your knowledge of endometriosis with this breakdown of terms related to the disease.

Medically reviewed in April 2022

When you’re learning about endometriosis, you may find some medical terms unfamiliar. This glossary will help you understand common words and phrases related to the symptoms, treatment, and science of the disease so you can feel more empowered to work with your healthcare team to make decisions about your health.

Bands of fibrous scar tissue that can cause internal organs to stick together, resulting in pain. Women with endometriosis may have adhesions throughout their pelvic area, including their uterus, ovaries, and bladder.

The clinical term for painful sexual intercourse. For some women with endometriosis, intercourse is painful or uncomfortable because penetration and other movements can stretch and pull endometrial growths.

A type of cyst that forms when endometrial tissue (the mucous membrane that makes up the inner layer of the uterine wall) grows in the ovaries. An endometrioma is sometimes referred to as a chocolate cyst because it contains old blood that can resemble melted chocolate.

A condition in which tissue that lines the inside of the uterus is found outside of the uterus, usually on the ovaries, fallopian tubes, and other pelvic structures.

The lining of the uterus that is shed during menstruation and that thickens during pregnancy.

The medical term for the surgical removal of the uterus. In a severe case of endometriosis, a woman and her healthcare team may decide on a hysterectomy as treatment.

The main tool that’s used during laparoscopic surgery (or keyhole surgery) to diagnose endometriosis and/or remove cysts, implants, and scar tissue caused by the endometriosis. The laparoscope has a light source and a lens that light up and project a magnified image of the pelvic cavity onto a screen. This way, the surgical team can have a clear view of the organs in the pelvis and any endometriosis present.

Laparoscopic surgery (or keyhole surgery)
A minimally invasive surgical procedure in which an instrument called a laparoscope is inserted into the pelvic cavity through a small incision (like a keyhole). The laparoscope is used to view the pelvic organs, diagnose endometriosis, and remove any cysts, implants, and scar tissue caused by the endometriosis. During the surgery, other small incisions may be made to allow for additional instruments.

The regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. It’s also known as “having your period.” Some women with endometriosis may experience pain and heavy bleeding during their period.

Ovaries are a pair of organs located on either side of the uterus and contain the eggs released at ovulation. The ovaries are also considered glands and produce hormones. Ovaries are one of the most common locations for endometriosis.

Secondary dysmenorrhea
In some cases, endometriosis is associated with pain during a menstrual period—sometimes severe pain. This is referred to as secondary dysmenorrhea because the pain is associated with a medical condition. Primary dysmenorrhea is pain that is associated with a normal menstrual period.

The organ between the bladder and rectum, which houses and nourishes the developing fetus during pregnancy. With endometriosis, the tissue that typically lines the inside of the uterus grows outside the uterus.

Medically reviewed in March 2020

endometriosis.org. "Adhesions."
Harvard Health Publishing. "Painful Sexual Intercourse (Dyspareunia)."
Brigham Health. "Deep Ovarian Endometriosis (Endometriomas)."
UpToDate. "Endometriosis: Management of ovarian endometriomas."
Molly Carnahan, Jennifer Fedor, Ashok Agarwal and Sajal Gupta. "Ovarian Endometrioma: Guidelines for Selection of Cases for Surgical Treatment or Expectant Management." Expert Review of Obstetrics & Gynecology, 2013. Vol. 8, No. 1.
Johns Hopkins Medicine. "Endometriosis."
endometriosis.org. "Glossary."
Office on Women's Health. "Hysterectomy."
Cleveland Clinic. "Surgical Treatment for Endometriosis."
Brigham Health. "Surgical Treatment of Endometriosis: Excision and Destruction."
Cleveland Clinic. "Normal Menstruation."
NCI Dictionary of Cancer Terms. "Ovary."
American College of Obstetricians and Gynecologists. "Patient Resources: FAQs."
MedlinePlus. "Uterus."
Cleveland Clinic. "Dysmenorrhea."

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