--- title: Haemorrhoidal disease came with a 24 percent higher rate of dementia over 15 years, and the authors say it is a marker, not a cause publication: Medical Insights Korea section: news category: Haemorrhoids canonical_url: https://medicalinsightskorea.com/news/korea-haemorrhoidal-disease-dementia-381031-cohort author: James Choi published: 2026-10-20T15:00:00+09:00 modified: 2026-10-20T15:00:00+09:00 content_type: reporting license: Quotation permitted with attribution to Medical Insights Korea and a link to the canonical URL. --- # Haemorrhoidal disease came with a 24 percent higher rate of dementia over 15 years, and the authors say it is a marker, not a cause 381,031 Koreans, a median 15.5 years of follow-up, and a hazard ratio of 1.243. The group who had their haemorrhoids treated came in at 0.925 — and that interval, unlike the heart failure one, does exclude 1. ## Answer In a population-based cohort of 381,031 participants in the South Korean health screening database between 2005 and 2010, followed for a median 15.49 years during which 80,488 cases of all-cause dementia accumulated (22.47 percent), participants with haemorrhoidal disease had a higher incidence of all-cause dementia after propensity score matching (hazard ratio 1.243, 95% CI 1.199 to 1.288), while those who underwent surgical procedures or treatment for it had a significantly lower incidence (HR 0.925, 95% CI 0.872 to 0.981) — a pattern the authors read as haemorrhoidal disease marking an underlying systemic condition rather than causing dementia. ## Key takeaways - 381,031 participants were drawn from the South Korean health screening cohort between 2005 and 2010. - Over a median 15.49 years of follow-up, 80,488 cases of all-cause dementia occurred — 22.47 percent of the cohort. - Haemorrhoidal disease carried a hazard ratio of 1.243 for all-cause dementia (95% CI 1.199 to 1.288) after propensity score matching. - Participants treated or operated on for haemorrhoidal disease had a hazard ratio of 0.925 (95% CI 0.872 to 0.981), an interval that excludes 1. - Alzheimer disease and vascular dementia were examined as secondary outcomes. - The authors state that haemorrhoidal disease may serve as a marker of an underlying systemic condition rather than directly causing dementia. - Haemorrhoidal disease was identified from at least two claims carrying ICD-10 code I84, and dementia from at least two claims under F00-F03, G30 or G31. ## Full article A hazard ratio of 1.243 across 381,031 people is not a borderline result, and the temptation with a finding like this is to dress it up. The research group did the opposite: their own discussion says haemorrhoidal disease may not directly cause dementia and may instead serve as a marker of an underlying systemic condition. That sentence is the reason the study is worth reading, and it is the part that gets dropped when a result like this travels. ### The size of it **1.243** — hazard ratio for all-cause dementia among participants with haemorrhoidal disease, after propensity score matching (95% CI 1.199 to 1.288) _Source: Woo HG et al., Frontiers in Neurology, 2025_ Follow-up ran to a median of 15.49 years, with an interquartile range of 12.21 to 18.77, which is long enough for dementia to be a realistic endpoint rather than a rare one: 22.47 percent of the cohort accumulated a diagnosis. A cohort this large and followed this long will detect small effects reliably, and 24 percent is not small. ### Why the marker reading is the better one No mechanism connects veins at the anal canal to the brain. What does connect them is everything in between: chronic straining, raised intra-abdominal and venous pressure, obesity, low physical activity, hypertension. A separate Korean screening cohort of 194,620 adults found hypertension independently associated with haemorrhoidal disease, and vascular risk factors are established contributors to dementia. Two conditions can share a cause without either causing the other. > **The treated group, and how it differs from the heart failure result** > The same research group reported a parallel analysis for heart failure in a cohort of 356,033 people. There the treated arm gave a hazard ratio of 0.941 with an interval of 0.880 to 1.001, which includes 1 and therefore does not exclude no effect. Here the treated arm gives 0.925 with 0.872 to 0.981, which does exclude 1. The difference matters when reporting them: one is a direction, the other is a result. Neither, though, licenses the conclusion people reach for — that treating haemorrhoids protects the brain. Being treated means having reached a doctor, and that selects for medical supervision, not just for surgery. ### What to do with it Nothing, clinically, in the direction most readers will expect. There is no case for operating on haemorrhoids to reduce dementia risk, and the study makes no such claim. What it supports is a more modest and more useful habit: haemorrhoidal disease is common enough and cheap enough to observe that it is a reasonable prompt to check the vascular risk factors sitting behind it — blood pressure, weight, activity — in a patient who came in about something else entirely. Both outcome definitions rest on insurance claims, so severity is invisible in both directions. Two claims under ICD-10 code I84 is a diagnosis of haemorrhoids, not a measure of how bad they were; two claims under F00 to F03, G30 or G31 is a diagnosis of dementia, not a stage of it. Every conclusion here sits at the resolution of diagnoses being recorded. ## Sources - Woo HG, Park MS, Park JY, Chun H, Song TJ. Association of hemorrhoidal disease with dementia risk: a nationwide cohort study. Frontiers in Neurology 2025;16:1655944. doi:10.3389/fneur.2025.1655944. PMID:41111974. https://doi.org/10.3389/fneur.2025.1655944 - Woo HG, Park JY, Park MS, Song TJ. The association of hemorrhoids with the incidence of heart failure: a nationwide cohort study. Annals of Translational Medicine 2025;13(2):14. doi:10.21037/atm-24-218. PMID:40438520. https://doi.org/10.21037/atm-24-218 ## Citation James Choi (2026). "Haemorrhoidal disease came with a 24 percent higher rate of dementia over 15 years, and the authors say it is a marker, not a cause". Medical Insights Korea. https://medicalinsightskorea.com/news/korea-haemorrhoidal-disease-dementia-381031-cohort Retrieved from https://medicalinsightskorea.com/news/korea-haemorrhoidal-disease-dementia-381031-cohort