Hidden Hernias in Women: CT Scans Reveal a Surprising Prevalence That Defies Medical Textbooks

One of the most common surgical conditions on the planet has a blind spot, and it is shaped like a woman’s groin. Inguinal and femoral hernias are famously regarded as a male problem, with lifetime prevalence figures of 27 to 43 percent in men against just 3 to 6 percent in women. That textbook gap, however, was built on evidence from cohorts that were roughly 84 percent male, leaving the female half of the population grossly understudied. Now a research team in Bogotá has taken a direct look at what abdominal computed tomography actually finds in women, and the numbers are turning the classical teaching on its head.

The new study, published in Frontiers in Radiology, analyzed 494 abdominal CT scans performed on adult women at a Colombian reference center serving the Bogotá–Sabana axis between 2024 and 2025. Rather than selecting patients with suspected hernias, the researchers combed through scans ordered for whatever reason the women originally came in, abdominal pain, oncologic follow-up, infections, trauma, or constitutional symptoms. This unfiltered, real-world design is precisely what makes the result so striking: the adjudicated prevalence of inguinal and femoral hernias on CT reached 16.8 percent, with a 95 percent confidence interval of 13.8 to 20.4 percent, well above the 3 to 6 percent range that clinicians have long quoted for women.

How the team arrived at that figure is as interesting as the number itself. Every scan was independently re-read by radiology residents in training, and any case was then put through a two-of-three majority adjudication involving the resident and two independent expert reviewers. The resident’s initial tally was 88 hernias, or 17.8 percent of the cohort. Expert review shaved that to 83 cases after five scans, exactly 1.0 percent of the total, were reclassified as something entirely different: extraperitoneal fat protruding into the inguinal canal without a true peritoneal sac.

That reclassification may sound like statistical hair-splitting, but it could be the study’s most consequential finding. Fat in the inguinal canal mimics a hernia on imaging but lacks the defining peritoneal sac, a distinction familiar from the spermatic cord lipoma literature in men. Its female equivalent, fat protrusion around the round ligament of the uterus, has been almost entirely absent from the literature. Because the female inguinal canal carries the round ligament rather than the spermatic cord, along with the canal of Nuck, an embryological remnant, the anatomy demands closer scrutiny than the male template provides. The five discordant cases, each called a hernia by the resident and consistently called normal by both experts, show that this overlooked differential diagnosis is not rare and accounts for much of the disagreement between readers.

The agreement statistics themselves tell a vivid story. Cohen’s kappa, which measures how much of the concordance between readers exceeds chance, was 0.878 between the resident and the first expert reviewer, nearly perfect on the standard Landis–Koch scale. Yet the same resident scored just 0.326 against the second expert, a fair rating, and the two experts scored 0.408 against each other, only moderate. Sensitivity of the resident readings was a flawless 100 percent against both experts, but specificity swung from 84.4 percent against Reviewer 1 to a mere 47.4 percent against Reviewer 2. The pattern is clear: the disagreement was not random sloppiness by a trainee but a deliberate difference in diagnostic threshold, with one expert applying a conservative criterion that penalized any hint of fat-only protrusion.

Within the 69 women whose hernias were fully characterized, the anatomy followed patterns that clinicians should note. Indirect inguinal hernias, those passing through the deep inguinal ring lateral to the inferior epigastric vessels, dominated, followed by direct inguinal and mixed subtypes. Femoral hernias accounted for 4.3 percent of cases, with another 5.8 percent showing mixed inguinal-plus-femoral configurations, consistent with reanalyses showing that femoral hernias are proportionally more common in women than men. Fully 26.1 percent of the characterized cases were bilateral, a novel tomographic figure for an unselected female cohort. The patients were strikingly old, with a mean age of 70.2 years and a median of 71, well above the median of 52 reported in mixed-cohort CT studies, consistent with postmenopausal connective tissue and pelvic floor changes that allow silent defects to declare themselves late in life.

Perhaps the most clinically sobering result concerns occult hernias, defined as CT-positive hernias for which no diagnosis or clinical suspicion existed before the scan. A substantial majority of the detected hernias fell into this hidden category, and many were also absent from the original radiology reports issued during routine care. This double invisibility, clinically and documentarily, echoes prior research showing that physical examination performs poorly in women, with occult hernias often misattributed for months or years to gynecological, musculoskeletal, or functional causes of groin and pelvic pain. Complications on imaging, meanwhile, were infrequent and mostly limited to intestinal obstruction, with no documented strangulation, suggesting that early detection could shift care toward elective, lower-risk pathways.

The authors are careful to frame the 16.8 percent as radiological rather than clinically manifest prevalence. Because the cohort captured every CT scan regardless of indication, the figure represents what tomography sees in women consulting for any reason, not the share of women who will ever present with a symptomatic hernia. The scans were also acquired without the Valsalva maneuver, which likely reduced sensitivity for small indirect hernias, and surgical confirmation was not systematically available, so the findings describe imaging diagnoses rather than operative gold standards. Even with those caveats, the number provides the first quantitative benchmark for a Colombian female cohort and a pointed correction to evidence built on populations dominated by men.

The study also offers a methodological gift to resource-limited settings. The two-of-three majority rule resolved discordance between three readers without external arbiters or in-person consensus meetings, preserving an explicit, auditable trail that satisfies STROBE reporting standards. In a Latin American context where diagnostic studies with more than two readers are rare, the researchers argue, this architecture costs nothing beyond prior operational organization, yet it converts subjective disagreement into a transparent, reproducible verdict.

The practical recommendations that follow are equally concrete: radiologists should routinely report the diagnostic pair of true inguinal hernia versus extraperitoneal fat protrusion with explicit anatomic criteria, standardize the incidental reporting of hernias spotted on scans ordered for other causes, and adopt second-reader structures for subtle findings where volume permits. If the Bogotá team’s numbers hold up across larger, multicenter cohorts with surgical validation, incidental CT may prove to be one of the highest-yield windows yet discovered into a condition that has quietly affected millions of women while the medical literature looked the other way.

Subject of Research: CT-based prevalence of inguinal and femoral hernias in women and interobserver agreement in radiological diagnosis

Article Title: CT-detected inguinal and femoral hernias in women: prevalence and interobserver agreement

Article References: Gómez Milanés, S., Quintero Rojas, O., Martínez, J., Ortiz, F., & González Serna, A. F. (2026). CT-detected inguinal and femoral hernias in women: prevalence and interobserver agreement. Frontiers in Radiology, 6, Article 1957651. https://doi.org/10.3389/fradi.2026.1957651

Image Credits: AI Generated

DOI: 10.3389/fradi.2026.1957651

Keywords: inguinal hernia, femoral hernia, computed tomography, women's health, radiology, interobserver agreement, extraperitoneal fat, occult hernia, prevalence, diagnostic imaging, Colombia, observational study