What is Endometriosis? Get Facts About This Chronic Disease
Author
Rina Carlini, PhD
Reviewed By
Rina Carlini, PhD and Joanne Tejeda, PhD
Published on
May 23, 2025

Endometriosis affects about 1 in 10 women and individuals with female reproductive anatomy. Endometriosis is a complex and chronic inflammatory condition where tissues that resemble the inner lining of the the uterus, the endometrium, grow in areas outside the uterus. Abnormal endometrial tissue growths are referred to as lesions. Endometriosis is categorized according to the size of lesions, location, and disease severity into 4 stages from least to most severe as Stage I, Stage II, Stage III, and Stage IV.

Examples of endometriosis according to the location of lesions in the body include:
Superficial peritoneal endometriosis (lesions on the pelvic cavity)
Ovarian endometriomas (lesions inside or on the ovary)
Deep infiltrating endometriosis (lesions on the bladder, rectovaginal septum, and sigmoid colon; this type is the most severe form)
Unfortunately, endometriosis is multi-factorial disease and manifests very differently from one person to the other, making its diagnosis incredibly challenging.
Endometriosis also has a negative impact on all aspects of quality of life - from personal and work relationships to mental health.
Symptoms
The most reported symptom is chronic pelvic pain (CPP) that worsens during the menstrual cycle. As the disease progresses, pain can evolve to include non-menstrual pelvic pain, including pain during intercourse.
Other symptoms include
Infertility,
Heavy menstrual bleeding
Irregular bleeding (spotting in between the menstrual cycle)
Irregular menstrual cycle
Chronic inflammation
Migraines
Depression
Painful bladder syndrome
Irritable bowel syndrome (IBS)
Uterine fibroids and ovarian cysts
Diagnosis and Treatment
As of today, the only way to truly confirm the presence of endometriosis is through laparoscopic surgery. Laparoscopy uses a device called a laparoscope; a thin tubular device that is equipped with a camera that is inserted into the abdomen to help guide the surgeon. During the surgery, if endometriosis is found, it is removed from the area to help relieve pelvic pain. The surgery can also temporarily aid with infertility. Despite being the current standard for diagnosis, laparoscopic procedures may not be available or recommended for some individuals as it is very invasive.
As such, alternative diagnostic methods are being explored and include:
Pelvic exam
Transvaginal and transabdominal ultrasounds
Magnetic Resonance Imaging (MRI)
Blood biomarkers (undergoing research)
Treatment for endometriosis often involves surgery to remove lesions, or other non-surgical treatment options for the management symptoms. Examples include:
Hormone Therapies:
Estrogen-progestin hormonal contraceptives (birth control pills)
Progestins (synthetic hormone drug)
Gonadotrophin-releasing hormone (GnRH) agonists
Danazol (androgenic steroid)
Pain Management Medication:
Non-steroidal anti-inflammatory drugs (NSAIDs) for pain management
Drug-free Pain Management Treatments:
Pelvic floor therapy
Acupuncture
Cognitive therapies
Digital therapies
Heating pads and warm baths
Due to the complicated nature of endometriosis and the overlap of symptoms with other gynecological issues such as pelvic pain, there is often a delay in diagnosis of 7-10 years, which means that many individuals continue to suffer without answers.
References
[1] Symons LK, Miller JE, Kay VR, et al. The Immunopathophysiology of Endometriosis. Trends Mol Med. 2018;24(9):748-762. doi:10.1016/j.molmed.2018.07.004
[2] As-Sanie S, Black R, Giudice LC, et al. Assessing research gaps and unmet needs in endometriosis. Am J Obstet Gynecol. 2019;221(2):86-94. doi:10.1016/j.ajog.2019.02.033
