5 Conditions Endometriosis Is Commonly Mistaken For—and Why Getting It Right Matters

Globally, it takes an average of 6.8 years for someone to get diagnosed with endometriosis.¹ In the US, some women face diagnostic delays of up to 11 years.² A large driver of this is the fact that endometriosis is often misdiagnosed as a different condition, with some studies showing misdiagnosis rates as high as 47%.³ Symptoms usually arise in adolescence, but with the delay, individuals often don’t get accurately diagnosed until they are in their late 20s. And this delay has severe downstream consequences, including disease progression, missed interventions, potential infertility, increased health care system costs, and more.

Endometriosis, a condition in which tissue resembling the uterine lining grows outside the uterus, affects roughly 170 million women globally. Despite being a leading cause of infertility, chronic pelvic pain, and reduced quality of life, it is estimated that about 60% of cases go undiagnosed.¹ Research shows that women with endometriosis are 3.3 times more likely to experience infertility and carry 1.75 times the direct medical costs of women without the condition, with hospitalizations occurring at more than twice the rate.⁴ Across the US, the total annual economic burden of endometriosis has been estimated as high as $78 billion to $119 billion, driven by both health care utilization and productivity losses.⁵

Despite this, there is not a lot of research into where exactly these delays are happening and what causes them. However, a contributing factor is the fact that endometriosis does not present in a single, recognizable way as its symptoms overlap substantially with several other common conditions, leading to repeated misdiagnosis and ineffective treatment. In fact, to date, the only definitive diagnostic standard technique remains laparoscopy, which was developed in the 1980s.⁶ Here are 5 of the most frequent diagnostic mix-ups and why they happen:

1. Gastrointestinal Conditions

Individuals with endometriosis are often misdiagnosed with various gastrointestinal conditions as one of the fundamental symptoms is gastrointestinal distress. This can present as cramping, bloating, diarrhea, constipation, and pain that fluctuates with the menstrual cycle. These symptoms mirror irritable bowel syndrome (IBS), which may lead to a misdiagnosis. Additionally, women with endometriosis have a greater overall risk of developing IBS.⁷ Because both conditions can worsen around menstruation and improve with dietary changes, clinicians may treat the gastrointestinal picture without ever considering a gynecological cause.

2. Uterine Fibroids

Heavy bleeding, pelvic pressure, and dysmenorrhea are shared features of both fibroids and endometriosis, making it easy to stop the diagnostic workup once fibroids are found on ultrasound. But the 2 conditions frequently co-exist. In fact, research has found that women with endometriosis have a 3- to 10-fold higher odds of fibroids compared with their counterparts.⁸ Treating fibroids alone when endometriosis is also present leaves a major driver of symptoms unaddressed.

3. Ovarian Cysts

Functional ovarian cysts are common and typically resolve on their own. Endometriomas, on the other hand, are ovarian cysts that form when endometrial tissue implants on the ovary, which may initially look similar on imaging, particularly when small. About 17 to 44% of individuals with endometriosis have endometriomas.⁹ Without careful radiologic interpretation and follow-up, an endometrioma may initially be mistaken for another benign ovarian cyst, delaying diagnosis of endometriosis. This distinction is important because untreated endometriomas can progressively damage ovarian tissue and negatively affect fertility.

4. Urinary Tract Infections

When endometrial tissue implants on or near the bladder or urethra, it can produce symptoms that closely mirror a urinary tract infection (UTI), which may lead to a misdiagnosis and therefore incorrect treatment administration.¹⁰ 

5. Pelvic Inflammatory Disease

Pelvic inflammatory disease (PID) causes pelvic pain, tenderness on exam, and, like endometriosis, can result in pelvic adhesions and scarring that produces pain outside of the menstrual cycle. In younger women or those with a history of sexually transmitted infections, PID may be the first explanation sought. While PID requires prompt treatment for infection, an endometriosis workup should follow if symptoms persist or recur without a clear infectious source.

Where Do We Go From Here?

Recognition of these diagnostic patterns is only part of the solution. Noninvasive diagnostic tools including improved serum biomarkers and advanced MRI protocols are an active area of research that could reduce reliance on laparoscopy, which is currently the only definitive diagnostic standard. Artificial intelligence–assisted imaging interpretation is also being explored as a means of detecting endometriomas and peritoneal lesions earlier. Clinical education efforts are increasingly focused on reducing the normalization of severe dysmenorrhea, which is one of the most persistent barriers to early referral. At a systems level, standardized referral pathways and improved documentation across care settings could help prevent the fragmented care trajectories that currently obscure diagnosis.

And progress is being made, as earlier this year the American College of Obstetricians and Gynecologists released new and updated clinical guidance on diagnosis of endometriosis, aiming to shorten time to diagnosis as well as access to care.²

All in all, earlier recognition means earlier intervention, preserved fertility, reduced suffering, and a smaller burden on patients and the health system alike. Getting the diagnosis right—and getting it sooner—is one of the most concrete ways clinicians can move the needle on women's health outcomes.

References

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2. ACOG publishes new endometriosis clinical guidance, aiming to shorten time to diagnosis and improve access to care. News release. American College of Obstetricians and Gynecologists. February 20, 2026. Accessed May 21, 2026. https://www.acog.org/news/news-releases/2026/02/acog-publishes-new-endometriosis-clinical-guidance-aiming-shorten-time-diagnosis-improve-access-care
3. Anwar R, Utomo A, Marlina D, et al. Misdiagnosis rate of endometriosis and strategies employed to identify endometriosis by analyzing patient characteristics in low-resource settings. SAGE Open Med. 2026;14:20503121261420031. doi:10.1177/20503121261420031
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7. Chiaffarino F, Cipriani S, Ricci E, et al. Endometriosis and irritable bowel syndrome: a systematic review and meta-analysis. Arch Gynecol Obstet. 2021;303(1):17-25. doi:10.1007/s00404-020-05797-8
8. Fiore A, Casalechi M, Sichenze L, Ferraro C, Magni B, Bellinghieri R, et al. Co-occurrence of endometriosis and uterine fibroids: a systematic review and meta-analysis. EClinicalMedicine. 2025. doi:10.1016/j.eclinm.2025.10351
9. Hoyle AT, Puckett Y. Endometrioma. StatPearls. StatPearls Publishing; 2026. Updated June 5, 2023. Accessed May 21, 2026. https://www.ncbi.nlm.nih.gov/books/NBK559230/
10. Kho RM. Urinary tract endometriosis has serious health implications. Consult QD. Cleveland Clinic. Published January 5, 2021. Accessed May 21, 2026. https://consultqd.clevelandclinic.org/urinary-tract-endometriosis-has-serious-health-implications