About Endometriosis

Endometriosis (from endo, “inside,” and metra, “womb”) is a term used to describe when  tissue that normally lines the uterus grows outside of it in patches (implants, nodules, lesions).

Endometriosis patches typically grow in the pelvic cavity:

  • Under or on the ovaries
  • Behind the uterus
  • On the bowels or bladder
  • On the fallopian tubes
  • On the tissues that hold the uterus in place

While rare, endometriosis can also occur in other parts of the body such as the lungs.

Who's at Risk?

An estimated 5 million women in the U.S. have endometriosis. It is most commonly found in women over the age of 30, but can affect any female who menstruates.

Make an Appointment

Call 858-657-8745

Clinical Trials Available

Do you have painful menstrual periods or pelvic pain at other times? To learn more about taking part in our research, call 619-940-4377. A researcher will contact you to discuss our current studies.

Q&A With Our Expert

Dr. Sanjay Agarwal answers three questions about endometriosis. Read it on Tumblr.

6 factors that may increase your risk for endometriosis:

  1. Periods started before age 11
  2. Menstrual cycles are heavy and last longer than 7 days
  3. Monthly cycles are shorter than 27 days
  4. Closed hymen (blocks flow of menstrual blood)
  5. Never had children
  6. Mother or sister have endometriosis (increases risk sixfold)

Symptoms of Endometriosis

Pain and infertility are primary symptoms of endometriosis.

Signs of endometriosis include:

  • Pain before and during periods
  • Pain with sex
  • Pain in the lower abdomen or intestine
  • Heavy menstrual periods
  • Infertility
  • Fatigue
  • Premenstrual bleeding/spotting between periods
  • Painful urination during periods
  • Painful bowel movements during periods
  • Frequent yeast infections
  • Other gastrointestinal upsets such as diarrhea, constipation, nausea


While there are several theories as to how endometriosis develops, the exact cause is unknown. The most popular theory is that endometriosis results from retrograde menstruation, a common condition in which tissue that's normally shed during a woman's period flows backward into the pelvic cavity. Only 6 to 10 percent of women who have retrograde menstruation develop endometriosis.

A combination of the following factors may also cause endometriosis:

  • Genes (family history of endometriosis)
  • Progesterone resistance
  • Immune system dysfunction
  • Environmental exposure (e.g., dioxin)
  • Excess estrogen