Endometriosis: A Glossary of Terms

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

A young woman holds a stack of books. Understanding key terms related to endometriosis can be helpful to patients.

Updated on November 29, 2023.

When you’re learning about endometriosis, you may find some of the medical terms related to the condition to be unfamiliar. This glossary can help you understand common words and phrases related to the symptoms, treatment, and science of the disease. With this information, 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. People with endometriosis may have adhesions throughout their pelvic area, including their uterus, ovaries, and bladder.


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


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


A condition in which tissue (endometrial tissue) that ordinarily 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 patient working with their healthcare team may decide to have a hysterectomy as treatment.


The main tool that’s used during laparoscopic surgery, also known as "keyhole" surgery. A laparoscopic procedure can be used to diagnose endometriosis and/or to remove cysts, implants, or scar tissue caused by endometriosis. The laparoscope is typically a thin tube equipped with a light source, a tiny camera, and other tools at the end. When the laparoscope is inserted into a small incision in the body, the light source and camera light up and project a magnified image of the pelvic cavity onto a computer screen. This way, the surgical team can have a clear view of the organs in the pelvis and can detect 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 to be used to treat endometriosis.


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 people with endometriosis may experience pain and heavy bleeding during their period.


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

Secondary dysmenorrhea

In some cases, endometriosis is associated with pain during a menstrual period. Sometimes the pain can be quite severe. 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 typical 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.

Article sources open article sources

Endometriosis.org. "Adhesions."
Harvard Health Publishing. "Painful Sexual Intercourse (Dyspareunia)."
Brigham Health. "Deep Ovarian Endometriosis (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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