{
  "slug": "endometriosis-diagnosis",
  "question": "What are the odds a woman will develop endometriosis?",
  "quick_answer": "About 1 in 10 reproductive-age women develop endometriosis. Most people have no clear sense of the prevalence and, if aware of the condition, tend to guess lower than reality.\n",
  "category": "health",
  "no_reliable_estimate": false,
  "perceived": {
    "description": "Endometriosis is simultaneously one of the most common gynecological conditions and one of the least intuitively understood in terms of its prevalence. Most adults cannot name a prevalence figure; those who can tend to significantly underestimate it. The condition's long diagnostic delay — averaging 7 to 11 years depending on the country — means that many women live with it for years before the word \"endometriosis\" ever appears in their medical record, which suppresses both public awareness and official prevalence figures. Surveys of women with endometriosis consistently report that they visited multiple providers before receiving a diagnosis, reinforcing a perception that the condition is rare when it is in fact common.\n",
    "rough_estimate": "Most adults have no clear prevalence estimate; those aware of the condition tend to guess lower than reality",
    "kind": "intuition"
  },
  "native": {
    "display": "~1 in 10 reproductive-age women worldwide",
    "numerator": 10,
    "denominator": 100,
    "unit": "lifetime",
    "population": "reproductive-age women, global"
  },
  "normalized": {
    "lifetime_us_adult": 0.1,
    "display": "1 in 10 lifetime (reproductive-age women)",
    "log_value": -1,
    "assumptions": "WHO estimates that endometriosis affects roughly 10% of reproductive-age women worldwide (~190 million). ACOG concurs with a ~1 in 10 figure for US women of reproductive age. A US National Survey of Family Growth (2011-2019) found a national self-reported prevalence of 6.4%, but this is widely considered an undercount because diagnosis requires either laparoscopy or advanced imaging, and many cases go undiagnosed for years. The true lifetime prevalence among women who live through their full reproductive years is likely closer to the 10% WHO figure, which is used here. Uncertainty band spans from the NSFG survey-based estimate (~0.06) to higher estimates from surgical series (~0.15) that include incidental findings in asymptomatic women undergoing surgery for other reasons.\n",
    "uncertainty": {
      "low": 0.06,
      "high": 0.15
    },
    "scope": "subgroup_lifetime"
  },
  "sources": [
    {
      "url": "https://www.who.int/news-room/fact-sheets/detail/endometriosis",
      "title": "Endometriosis — fact sheet",
      "publisher": "World Health Organization",
      "source_type": "govt_report",
      "statistic": "Endometriosis affects roughly 10% (190 million) of reproductive-age women and girls globally",
      "excerpt": "\"Endometriosis affects roughly 10% (190 million) of reproductive age women and girls globally. [...] There is currently no known way to prevent endometriosis. Enhanced awareness, followed by early diagnosis and management, may slow or halt the natural progression of the disease.\"\n",
      "source_date": "2025-03-28",
      "source_accessed": "2026-04-24",
      "archive_url": "http://web.archive.org/web/20260422235413/https://www.who.int/news-room/fact-sheets/detail/endometriosis",
      "calculation_notes": "WHO gives the headline 10% figure directly. This is a prevalence estimate, not incidence, and covers women of reproductive age (~15-49). It is based on a synthesis of epidemiological studies and is the most widely cited global figure. The denominator is all reproductive-age women, not just those who have undergone diagnostic surgery, so it implicitly includes estimated undiagnosed cases.\n",
      "independence_note": "WHO synthesises multiple epidemiological studies into a consensus prevalence figure. Methodologically distinct from the ACOG clinical guidance below, though both draw on overlapping literature.\n"
    },
    {
      "url": "https://www.acog.org/womens-health/faqs/endometriosis",
      "title": "Endometriosis",
      "publisher": "American College of Obstetricians and Gynecologists",
      "source_type": "reputable_reference",
      "statistic": "Endometriosis occurs in about 1 in 10 women of reproductive age",
      "excerpt": "\"Endometriosis occurs in about 1 in 10 women of reproductive age. [...] Endometriosis is most often diagnosed in women in their 30s and 40s.\"\n",
      "source_date": "2024-12-01",
      "source_accessed": "2026-04-24",
      "archive_url": "http://web.archive.org/web/20260426200607/https://www.acog.org/womens-health/faqs/endometriosis",
      "calculation_notes": "ACOG's 1-in-10 figure aligns with the WHO consensus. ACOG notes that prevalence is much higher among women with subfertility or chronic pelvic pain, but the headline figure refers to the general population of reproductive-age women. Average diagnosis delay of 7-11 years means that cross-sectional prevalence studies undercount true lifetime prevalence.\n",
      "independence_note": "ACOG is a US clinical-guidance body that synthesises peer-reviewed literature independently of WHO, though both draw on many of the same underlying studies.\n"
    },
    {
      "url": "https://www.endometriosis-uk.org/diagnosis-report",
      "title": "Years of being \"dismissed, ignored and belittled\": Endometriosis UK urges improvement to deteriorating diagnosis times",
      "publisher": "Endometriosis UK",
      "source_type": "reputable_reference",
      "statistic": "In a 2023 survey of 4,371 people with endometriosis, 47% had visited their GP 10 or more times, and 70% had visited 5 or more times, with symptoms before receiving a diagnosis",
      "excerpt": "\"Almost half of all respondents (47%) had visited their GP 10 or more times with symptoms prior to receiving a diagnosis, and 70% had visited 5 times or more.\"\n",
      "source_date": "2024-03-01",
      "source_accessed": "2026-07-03",
      "archive_url": "http://web.archive.org/web/20260711165644/https://www.endometriosis-uk.org/diagnosis-report",
      "calculation_notes": "Endometriosis UK's own diagnosis-delay survey (N=4,371), published for Endometriosis Action Month 2024. This is a UK patient population, not a US one, but is used as evidence for the diagnostic-delay structural pattern described in the body prose, alongside the global WHO/ACOG prevalence figures. Not used for the entry's headline prevalence number.\n",
      "independence_note": "Endometriosis UK is a patient charity conducting its own member/patient survey, independent of the WHO and ACOG prevalence syntheses above.\n"
    },
    {
      "url": "https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1576490/full",
      "title": "Factors contributing to the delayed diagnosis of endometriosis — a systematic review and meta-analysis",
      "publisher": "Frontiers in Medicine (Li, Feng & Ye, 2025)",
      "source_type": "peer_reviewed",
      "statistic": "Pooled mean diagnostic delay declined from approximately 9.8 years (1990-2000) to 5.6 years (2011-2020) across included studies, but reported diagnosis times still range from 4.4 to more than 10 years depending on country/region",
      "excerpt": "\"even in the current century, with increased awareness of the disease and medical advancements, significant delays are observed, and diagnosis times vary between 4.4 years and more than 10 years.\"\n",
      "source_date": "2025-07-22",
      "source_accessed": "2026-07-03",
      "archive_url": "http://web.archive.org/web/20260309082720/https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2025.1576490/full",
      "calculation_notes": "This meta-analysis pools mean diagnostic-delay figures across studies grouped into three periods (1990-2000, 2001-2010, 2011-2020), showing a downward trend (approx. 9.8 to 5.6 years) alongside continued substantial delay in absolute terms. Used in the body prose to support the claim that diagnostic delay remains a persistent structural problem even as it has gradually improved, replacing an earlier draft claim that delay was \"not shrinking appreciably,\" which this source does not support (it documents gradual improvement) even though it does confirm delays remain multi-year in every region studied.\n",
      "independence_note": "Independent peer-reviewed meta-analysis, methodologically distinct from the WHO/ACOG consensus prevalence figures and the Endometriosis UK patient survey above.\n"
    }
  ],
  "comparison_anchors": [
    {
      "label": "PCOS diagnosis (lifetime, women)",
      "lifetime_us_adult": 0.1
    },
    {
      "label": "Uterine fibroids by age 50 (US women)",
      "lifetime_us_adult": 0.7
    },
    {
      "label": "Breast cancer diagnosis (lifetime, US women)",
      "lifetime_us_adult": 0.13
    },
    {
      "label": "Ovarian cancer diagnosis (lifetime, US women)",
      "lifetime_us_adult": 0.011
    }
  ],
  "personal_factor_multipliers": [
    {
      "factor": "First-degree relative with endometriosis",
      "multiplier": 5,
      "notes": "Family history is one of the strongest risk factors; first-degree relatives of affected women have roughly 5-7x elevated risk"
    },
    {
      "factor": "Subfertility or chronic pelvic pain",
      "multiplier": 3,
      "notes": "Prevalence among women with subfertility reaches ~50-70% in surgical series; this reflects diagnostic selection bias as well as true elevation"
    },
    {
      "factor": "Early menarche (before age 11)",
      "multiplier": 1.5,
      "notes": "Earlier and longer lifetime menstrual exposure is associated with modestly higher risk"
    },
    {
      "factor": "Multiparity (3+ births)",
      "multiplier": 0.5,
      "notes": "Pregnancy and breastfeeding suppress menstruation and appear protective"
    }
  ],
  "short_label": "Endometriosis",
  "myth_framing": "underrated",
  "outcome_severity": "serious_harm",
  "exposure_pattern": "recurring",
  "outcome_type": "chronic_illness",
  "valence": "negative",
  "caveats": "Endometriosis prevalence figures are inherently uncertain because definitive diagnosis historically required laparoscopic surgery, and many affected women never receive a diagnosis. The WHO/ACOG 10% figure is a consensus estimate that attempts to account for undiagnosed cases, but the true figure could be meaningfully higher or lower. The 7-11 year average diagnostic delay is one of the longest of any common medical condition, which means that point-in-time prevalence studies systematically undercount. This entry uses the prevalence figure (proportion of women who will have the condition at some point) rather than an annual incidence rate, because endometriosis is a chronic condition that does not have a clean \"event per year\" structure.\n",
  "quality_score": {
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    "d2": 4,
    "d3": 5,
    "d4": 4,
    "d5": 5,
    "d6": 5,
    "d7": 4,
    "d8": 4,
    "avg": 4.25,
    "scored_by": "extracted-from-transcript",
    "scored_at": "2026-05-03",
    "methodology_version": "1.0"
  },
  "reviewer": "8d-eval-2026-05-16",
  "last_reviewed": "2026-05-16",
  "reviewed": true,
  "generated_at": "2026-04-24",
  "image": {
    "alt": "Scattered pale irregular shapes on a muted dusty-rose background, flat vector illustration suggesting hidden complexity."
  },
  "attribution": "Likelier — https://likelier.app",
  "license": "https://creativecommons.org/licenses/by-sa/4.0/",
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}