What is Endometriosis?
Endometriosis is a chronic inflammatory disease where tissue similar to the lining of the uterus (endometrium) grows outside the uterus, causing pelvic pain and infertility 1.
The Basic Problem
Think of endometriosis as tissue that normally belongs inside the uterus showing up in the wrong places. This misplaced tissue can grow on:
- The ovaries
- Fallopian tubes
- The outer surface of the uterus
- The lining of the pelvic cavity
- The bladder or bowel
- Other abdominal organs
This tissue behaves like normal uterine lining—it responds to hormones during your menstrual cycle, thickening and breaking down each month, but it has nowhere to go 2. This causes inflammation, scarring, and the formation of adhesions (bands of scar tissue that can make organs stick together).
How Common Is It?
Endometriosis affects approximately 176 million women worldwide, or about 10% of women of reproductive age 1, 3. In adolescents with chronic pelvic pain, up to 47% may have endometriosis, and nearly 70% of girls with severe period pain that doesn't respond to standard pain medications may have the condition 4.
What Causes It?
The most widely accepted explanation is retrograde menstruation 2, 5:
- During your period, menstrual blood flows backward through the fallopian tubes into the pelvic cavity (this happens in 76-90% of women)
- Endometrial cells in this blood can implant and grow on pelvic surfaces
- However, since most women experience retrograde menstruation but only 10% develop endometriosis, other factors matter: genetic predisposition, immune system differences, hormonal factors, and environmental influences 5, 3
What Does It Feel Like?
The hallmark symptoms include 6, 2:
- Dysmenorrhea: Severe, often debilitating menstrual cramps
- Chronic pelvic pain: Pain that persists beyond periods
- Deep dyspareunia: Pain during or after sexual intercourse
- Dyschezia: Painful bowel movements, especially during periods
- Dysuria: Painful urination
- Infertility: Difficulty getting pregnant
A critical caveat: the severity of symptoms does not correlate with the extent of disease—some women with minimal endometriosis have severe pain, while others with extensive disease may have few symptoms 1.
Impact on Quality of Life
Endometriosis is estrogen-dependent and manifests during reproductive years, significantly affecting physical health, emotional well-being, fertility, and overall quality of life 1, 6, 2. The disease imposes substantial burdens on individuals and healthcare systems, often complicated by diagnostic delays averaging several years 3, 7.
Important Clinical Points
- Diagnosis is often delayed because symptoms can be dismissed as "normal" period pain 4, 6
- The disease can be confirmed definitively only through direct visualization (laparoscopy) and biopsy, though clinical diagnosis based on symptoms is increasingly accepted, especially in adolescents 4, 8
- Endometriosis is associated with a 50% increased risk of epithelial ovarian cancer, though the absolute risk remains low 2
- The condition is chronic and often recurs even after treatment 2, 7