What is Endometriosis?
Endometriosis is an inflammatory disease characterized by endometrial-like tissue growing outside the uterus, affecting approximately 10% of individuals assigned female at birth during their reproductive years, causing pelvic pain and/or infertility. 1
Definition and Prevalence
Endometriosis is defined by the presence of endometrial-like tissue (lesions) outside the uterine cavity, typically in the pelvis, causing inflammation and fibrosis. 1 It affects:
- Approximately 10% of women worldwide during reproductive years
- An estimated 176 million women globally 1
- 9 million women in the United States 2
Classification
Endometriosis is classified based on location and depth into three main types:
- Peritoneal (superficial) - lesions on the peritoneal surface
- Ovarian endometriomas - cystic lesions in the ovaries
- Deep endometriosis (DE) - extends deeper than 5mm under the peritoneal surface or involves/distorts bowel, bladder, ureter, or vagina 1
Clinical Presentation
Common Symptoms
- Pain manifestations (present in 90% of patients): 2
- Dysmenorrhea (painful periods)
- Nonmenstrual pelvic pain
- Dyspareunia (painful intercourse)
- Fertility issues (reported in 26% of patients) 2
- Other symptoms:
- Fatigue
- Gastrointestinal symptoms
- Urinary symptoms
- Mood disorders 1
Risk Factors
- Younger age at menarche
- Shorter menstrual cycle length
- Lower body mass index
- Nulliparity
- Congenital obstructive müllerian anomalies 2
Modern Understanding of Endometriosis
Recent research has evolved our understanding of endometriosis from a localized gynecological condition to a chronic systemic disease: 3
- Affects metabolism in liver and adipose tissue
- Leads to systemic inflammation
- Alters gene expression in the brain causing pain sensitization and mood disorders
- Has manifestations beyond the pelvis 3
Diagnosis
Diagnosis of endometriosis is often significantly delayed:
- Average delay of 5-12 years after symptom onset
- Most women consult 3 or more clinicians prior to diagnosis 1, 2
Diagnostic Approaches
- Clinical diagnosis based on symptoms
- Imaging support:
- Transvaginal ultrasound (TVUS)
- Pelvic MRI 1
- Definitive diagnosis traditionally requires surgical visualization of lesions, though modern approaches are moving toward non-surgical diagnosis 2
Important Caveat
Normal physical examination and imaging do not exclude the diagnosis of endometriosis 2
Impact on Quality of Life
Endometriosis substantially affects quality of life by:
- Interfering with daily activities
- Affecting work performance
- Disrupting relationships
- Creating an economic burden estimated at $69.4 billion annually 1
Treatment Approaches
Treatment depends on the patient's goals and symptom severity:
First-line Treatments
- Hormonal medications:
- Combined oral contraceptives
- Progestin-only options 2
Second-line Treatments
- GnRH agonists and antagonists 2
Third-line Treatments
- Aromatase inhibitors 2
Surgical Options
- Laparoscopic removal of lesions (when hormonal therapies are ineffective or contraindicated)
- Hysterectomy with removal of lesions (for refractory cases) 2
Treatment Efficacy Considerations
- 11-19% of individuals have no pain reduction with hormonal medications
- 25-34% experience recurrent pelvic pain within 12 months of discontinuing hormonal treatment
- Approximately 25% of patients who undergo hysterectomy experience recurrent pelvic pain 2
Endometriosis is increasingly recognized as a complex, multisystem disease requiring comprehensive management strategies that address both the physical lesions and the systemic manifestations of the condition. 4