I read that haemorrhoids are linked to dementia and heart failure. Should I be worried?

Both studies exist, both are large, and both come from the same Korean research group. A hazard ratio of 1.243 for dementia across 381,031 people is not a fluke of small numbers. The question is what it means, and the answer is in the papers themselves.

What the researchers concluded#

The dementia paper's own discussion says that while haemorrhoidal disease may not directly cause dementia, it may serve as a marker of an underlying systemic condition that increases dementia risk. That sentence is the most important one in either study and it is the first thing dropped when a finding like this travels through headlines.

What could produce both at once#

No pathway connects dilated veins at the anal canal to the brain or to cardiac function. What does connect them is everything in between: chronic straining, raised intra-abdominal and venous pressure, obesity, low physical activity and 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.

So what should you actually do#

Nothing in the direction the headline suggests. There is no case for treating haemorrhoids to reduce dementia or heart failure risk, and neither study makes that claim. What is reasonable is smaller and free: if you have haemorrhoidal disease, it is a sensible prompt to have your blood pressure and weight checked, because the vascular risk these studies are probably detecting is the thing that can be acted on.

Both studies identified conditions from insurance claims — two entries under a diagnostic code — so severity is invisible on both sides. They describe diagnoses being recorded, not disease being measured, and every conclusion sits at that resolution.