Age by itself is not what determines the outcome — a Korean series found perioperative results in patients over 80 were influenced by the severity of the gallbladder disease rather than by chronological age — and the risk of not operating is substantial: among 29,818 Medicare patients admitted urgently with acute cholecystitis, the 25 percent who did not have their gallbladder removed during that admission had a 38 percent gallstone-related readmission rate over the next two years against 4 percent in those who did.
Both routes are in routine use — clearing the duct endoscopically first and removing the gallbladder afterwards, or doing both in a single laparoscopic operation — and a meta-analysis of 13 studies covering 1,757 patients found the single-operation route cleared the duct in 94.1 percent of cases against 90.1 percent, with fewer perioperative complications, fewer retained stones and a shorter stay, while deaths did not differ.
Yes: a Korean multivariable analysis of 58 patients having gallbladder removal after gastrectomy found the laparoscopic approach feasible as the initial approach even where common bile duct stones or acute cholecystitis were present, with one open conversion in the series, and it was independently associated with a shorter hospital stay rather than a longer operation or more complications.
Mirizzi syndrome is a gallstone impacted at the neck of the gallbladder that first compresses the bile duct from outside and can go on to erode into it, and it changes the operation rather than the diagnosis of gallstones: a systematic review of laparoscopic treatment reported conversion to open surgery in 41 percent of cases, complications in 20 percent and reoperation in 6 percent.
The robotic approach reliably reduces one thing, conversion to open surgery, and reliably costs about twice as much, but on bile duct injury the evidence does not support calling it better: one meta-analysis of 1,770,300 patients found no significant difference (odds ratio 1.42, 95 percent confidence interval 0.43 to 4.66) while another of more than 412,000 found injury in 0.72 percent of robotic against 0.23 percent of laparoscopic cases (relative risk 3.12, 2.34 to 3.91) — and because the first interval contains the second estimate, the two are compatible, meaning the reassuring review was imprecise rather than reassuring.
In 2,514 patients having laparoscopic gallbladder removal at 18 Korean academic hospitals, 62 (2.5 percent) had a surgery-related complication and 17 (0.7 percent) had a bile duct injury — the complication that matters most, because in an Irish national series of 34 patients treated for it, 29.4 percent needed re-operation, one needed a liver transplant and 12.5 percent died around the time of surgery.
Korean national cohorts do find more hepato-biliary-pancreatic cancer diagnosed after gallbladder removal — an incidence rate ratio of 1.08 across 715,872 patients against 1,431,728 matched controls — but the excess is concentrated in the first one to three years after surgery and returns to the level of matched controls after five to ten years, which is the pattern expected when the cancer was already present rather than caused by the operation.
Diarrhoea after gallbladder removal affected 13.3 percent of 3,476 patients pooled across 21 studies in a systematic review, and is attributed to bile draining continuously into the intestine rather than being released after meals, so that bile acids reach the colon and draw water into it.
Most people live normally after their gallbladder is removed, because the liver continues to produce bile and it drains into the intestine continuously instead of being stored. A pooled analysis of 3,476 patients found 13.3 percent developed diarrhoea, and a meta-analysis of 2,948 patients put the rate of persistent post-cholecystectomy symptoms at 3.21 percent.
European guidelines recommend cholecystectomy for gallbladder polyps measuring 10 mm or more, while the Korean Society of Abdominal Radiology's 2025 recommendations advise surgery at 15 mm and treat 10–14 mm polyps without concerning imaging features as optional — so the size that triggers surgery depends on which guideline a hospital follows.
Most gallstones that have never caused symptoms do not go on to cause them: a 2026 meta-analysis of 25,924 people found about 10 percent became symptomatic within five years and 19 percent within ten, and its authors recommend conservative management rather than preventive surgery for most patients.
Korean national data suggest it carries a real psychological cost: in a target trial emulation matching men with localised prostate cancer, those who had surgery or radiotherapy were less likely to start antidepressants than matched men under surveillance — hazard ratios of 0.73 (95% CI 0.58 to 0.93) for surgery and 0.38 (0.24 to 0.61) for radiotherapy — over a mean follow-up of 4.4 years.
More often than not, yes: in 27,075 biopsy-confirmed Korean prostate cancer cases from 51 general hospitals, 14,609 — 53.9 percent — were high-risk at diagnosis, against 5.45 percent low-risk, and the share of low-risk disease at diagnosis fell from 11.4 percent in 2010 to 7.6 percent in 2020.
Androgen deprivation therapy affects far more than the prostate: in a two-year study of 115 men starting it, bone mineral density fell significantly at every measured site in those not given zoledronic acid — by 3.0 to 5.0 percent — and bone microarchitecture and strength at the wrist and ankle declined even in those who were, while a Korean national cohort of 10,168 propensity-matched pairs found a higher risk of Alzheimer's disease (adjusted hazard ratio 1.39, 95% CI 1.21 to 1.59) though not of overall dementia, vascular dementia or Parkinson's disease.
Bowel function is radiotherapy's distinctive harm: in the ProtecT trial, which randomised 1,643 men and followed patient-reported outcomes for six years, bowel function was worse in the radiotherapy group at six months and then partly recovered — except for bloody stools, which became more frequent over time — while radiotherapy had little effect on urinary continence, the function surgery damaged most.
The risk is partly predictable before surgery: a meta-analysis of 48 studies and 12,620 men found that incontinence within three months of robot-assisted radical prostatectomy was independently predicted by age (odds ratio 1.04 per year), membranous urethral length on preoperative MRI (0.83 per millimetre, longer being protective), International Prostate Symptom Score (1.03 per point), body mass index and prostate volume.
The dizziness is a drop in blood pressure on standing, and it does raise the risk of falling — but almost entirely at the start. In a Korean national cohort of 53,303 matched pairs of men aged 60 to 75, alpha-antagonists prescribed for benign prostatic hyperplasia carried an odds ratio for falls of 1.80 (95% CI 1.62 to 2.00), and of the 968 falls recorded in the treated group 455 — 47 percent — happened on the first day of medication, with a further excess in summer (OR 1.23); the same class showed no association with heart failure in a separate Korean cohort of 22,540 men (HR 1.14, 95% CI 0.87 to 1.49).
For localised prostate cancer, the randomised evidence at 15 years found no significant difference in prostate cancer death between active monitoring, surgery and radiotherapy (3.1, 2.2 and 2.9 percent respectively, P equals 0.53), but monitoring carried roughly twice the rate of metastasis and progression, while surgery carried the worst effects on continence and sexual function.
PSA testing does reduce prostate cancer deaths, but by a small absolute amount and at the cost of diagnosing cancers that would never have caused harm: at 23 years the European screening trial found 13 percent lower prostate cancer mortality, an absolute risk reduction of 0.22 percent, one death prevented per 456 men invited, and 30 percent more cancers diagnosed.
For intrathyroidal low- to intermediate-risk thyroid cancer under 4 cm, removing half the gland gives survival equivalent to removing all of it — in 918 propensity-matched pairs, ten-year overall survival was 92.2 against 91.3 percent and disease-specific survival 100 against 99.1 percent — and if the rest has to come out later, that second operation carries a safety profile similar to having taken everything at once; but the main reason patients choose the smaller operation does not hold reliably, because 46.6 percent of people who keep half a thyroid start thyroid hormone within twelve months.
Thyroid surgery can be performed through the armpit or the mouth rather than the front of the neck, leaving no visible neck scar, and Korea originated and performs most of these operations: but the pooled figure that makes the transaxillary approach look safest — 1 percent transient nerve injury, the lowest of any approach — compares patients selected for it against everyone else rather than testing it head to head, and a Korean series of 1,000 consecutive transaxillary robotic operations that confirmed nerve injury by laryngoscopy rather than by hoarseness found 4.1 percent.
After total thyroidectomy the thyroid hormone levothyroxine is taken permanently, because the gland producing it is gone; after hemithyroidectomy it is not automatic but is common, with 236 of 507 patients (46.6 percent) starting levothyroxine within twelve months and 55.9 percent of those starting within the first three.
Voice change after thyroid surgery is common and usually temporary, and it happens even when the nerves are undamaged: in 527 patients with intact vocal fold movement and normal nerve conduction, pitch fell immediately after surgery and self-rated voice handicap rose before returning to near-baseline by six to twelve months, while permanent nerve injury itself occurs in roughly 1 to 2 percent of operations.
A thyroid nodule found on a screening ultrasound is a common incidental finding rather than a diagnosis: a meta-analysis of 95,394 asymptomatic adults found 30.6 percent had one, most smaller than one centimetre, and Korea's experience shows that scanning for them produced a fifteen-fold rise in thyroid cancer diagnoses with no corresponding fall in thyroid cancer deaths.
Screening multiplied thyroid cancer diagnoses in South Korea without a matching change in deaths: incidence rose 6.4-fold between 1999 and 2008, with 94.4 percent of the increase consisting of tumours smaller than 20 mm found mainly by screening, while an international analysis attributed more than 85 percent of Korean female cases in 2013–17 to overdiagnosis.
For low-risk papillary thyroid microcarcinoma the Korean Thyroid Association's 2025 guideline permits active surveillance — monitoring rather than removing the tumour — in patients with no lymph node or distant metastasis, no gross extension beyond the thyroid, no invasion of the trachea or recurrent laryngeal nerve, and no aggressive histology.
Yes. In a time-series analysis of 687,833 urolithiasis patients across six Korean cities from 2009 to 2013, presentations rose with daily mean temperature and fell with humidity in every city, with the effect appearing within five days — and national emergency data show an August peak of 35,927 visits against 24,008 in February.
Probably not, for passing the stone itself. In the SUSPEND trial of 1,136 adults with a single ureteric stone, 80 percent on placebo needed no further intervention within four weeks against 81 percent on tamsulosin and 80 percent on nifedipine — four in five passed the stone whatever they took.
It matters, because prevention differs by composition. In 33,078 Korean stone analyses collected between 2014 and 2019, calcium oxalate was the largest group at 46.41 percent, followed by struvite at 29.66 percent, uric acid at 19.61 percent and calcium phosphate at 4.32 percent.
Not automatically. In the NOSTONE trial, 416 patients with recurrent calcium stones took hydrochlorothiazide at 12.5, 25 or 50 mg daily or placebo for a median of 2.9 years, and recurrence was 59, 56, 49 and 59 percent respectively, with no dose-response and more side effects on the drug.
About one in five Korean patients diagnosed with a urinary stone has another within five years: in a National Health Insurance Service cohort of roughly one million people, 21.3 percent recurred inside five years, and the estimated lifetime prevalence of urinary stones in Korea is 11.5 percent.
Both changed, and the counting is the half usually left out: on 1 January 2024 Korea moved syphilis from sentinel surveillance, in which a designated sample of sites report, to mandatory surveillance, in which every diagnosed case must be reported, and expanded the reporting criteria at the same time — so the 2,790 cases and incidence of 5.4 per 100,000 recorded for 2024 were not measured the way the 3.41 per 100,000 reported for 2019 was, and subtracting one from the other measures the change in the system as much as the change in the disease; the underlying rise is nevertheless real, having climbed from 1.93 per 100,000 in 2011 to 3.41 in 2019 under the old system and risen sharply in men in their twenties and thirties since 2016, which is precisely where the 2024 cases concentrate.
Not necessarily, and in Korea the gap between a positive panel and an infection is wide: across 1,399,431 multiplex PCR tests performed nationwide between 2021 and 2024, 67.23 percent were positive for at least one of the twelve organisms tested, but the commonest findings were Gardnerella vaginalis at 64.70 percent, Ureaplasma parvum at 41.37 percent and Candida albicans at 18.07 percent — organisms that live in the genital tract of many people without causing disease — while the 2023 Korean sexually transmitted infection guidelines state plainly that Ureaplasma urealyticum, Ureaplasma parvum and Mycoplasma hominis are regarded as symbiotic bacteria, are usually not considered sexually transmitted infections, and do not require treatment unless they are suspected of being associated with infertility.
A positive HPV test says the virus is detectable now and says nothing about when it was acquired: HPV positivity fluctuates across a person's life, the virus can persist below the threshold at which tests detect it and be found again later, and what research calls clearance usually means only that viral DNA fell below the clinical detection level rather than that the infection ended — so a first positive result years into a relationship is entirely compatible with an infection acquired long before it, and the test cannot establish infidelity in either direction.
Korea's national immunisation programme vaccinates girls only, with the quadrivalent vaccine, while a dynamic transmission model built for the Korean population projects that gender-neutral vaccination with the nonavalent vaccine would prevent 666,182 cases of genital warts, 995 anal cancers and 2,441 head and neck cancers in men over 100 years at an incremental cost-effectiveness ratio of 38.9 million won per quality-adjusted life year — below Korea's accepted threshold — and a global meta-analysis of 68 million participants found direct vaccination reduced vaccine-type HPV infection in males aged 13 to 26 by a relative risk of 0.35.
Every available treatment for anogenital warts removes visible lesions rather than clearing the underlying HPV infection, so warts can return afterwards, and no reliable figure exists for how often: a network meta-analysis of 37 randomised trials that included recurrence as an outcome concluded that the quality of the evidence taken as a whole is low and that few studies compare treatments against each other at all — while a separate meta-analysis found that HPV subtype, the thing most often offered as an explanation, does not significantly predict recurrence.
Usually not. Cervical cancer screening is not recommended after hysterectomy in the absence of a history of cervical intraepithelial neoplasia grade 2 or higher, yet in the 2014 to 2016 Korean National Cancer Screening Survey of 6,807 women aged 30 to 74, 61.8 percent of women who had undergone a hysterectomy had been screened in the previous two years against 64.7 percent of women with an intact uterus — and among women aged 30 to 44 the position reversed outright, 77.8 percent of those with a hysterectomy against 57.1 percent of those without.
The published evidence shows it generating procedures rather than answers. In the Study of Health in Pomerania, 3,371 of 6,753 participants had whole-body magnetic resonance imaging and 8,208 incidental findings were disclosed to 4,707 participants, after which biopsy rates rose from 6.9 to 9.9 per 100 observation years — and the rise fell disproportionately on biopsies that found nothing malignant, with a non-malignant biopsy rate ratio of 1.39 (95% CI 1.22 to 1.58) among participants who received a disclosure against 1.09 (0.85 to 1.38) among those who did not.
What scales dependably with price is radiation. In an analysis of 190 comprehensive health examination programmes at ten Seoul university hospitals, 132 (69.5 percent) included computed tomography and the average effective dose ran from 3.62 mSv for an intensive disease-specific programme to 11.12 mSv for an intensive cancer programme, 18.14 mSv for a premium programme and 24.08 mSv for an overnight programme — between 3.6 and 24 times the annual public dose limit — with cost correlating with dose at r = 0.812, while the 2019 Cochrane review of general health checks found no effect on total mortality across 11 randomised trials and 233,298 participants (RR 1.00, 95% CI 0.97 to 1.03, high-certainty evidence).
A Korean comprehensive health checkup is a bundle of separate tests whose evidence differs test by test: within Korea's own national programme, upper endoscopy is associated with roughly half the odds of dying from gastric cancer while the upper gastrointestinal series shows no association at all, randomised trials of general health checks as a whole find no reduction in total mortality (risk ratio 1.00, 95 percent confidence interval 0.97 to 1.03), and the thyroid ultrasound commonly bundled in is the test that produced the world's largest cancer overdiagnosis epidemic — so the answerable question is not whether to have a checkup but which tests are in it.
Equivalent on the main outcome, more comfortable afterwards. In a systematic review and meta-analysis of 21 studies covering 7,844 patients and 9,677 limbs, cyanoacrylate ablation and endovenous radiofrequency ablation showed no significant difference in great saphenous vein occlusion rate or Venous Clinical Severity Score, while cyanoacrylate produced less ecchymosis (5.96 against 10.97 percent, P = .01), less paraesthesia (1.24 against 2.97 percent, P = .04) and a shorter procedure time — but rare serious harms specific to the glue, including a fatal pulmonary embolism and a severe granuloma, appear only as case reports and are not counted in that comparison.
Largely yes. In a Korean national survey of chronic venous disease about 60 percent of patients said physical symptoms rather than appearance were what harmed their quality of life, so the main driver of harm is absent in someone without symptoms — and while a Taiwanese nationwide cohort of 4,644 patients found 1.37 times the mortality (95% CI 1.19 to 1.57) and 2.05 times the rate of major adverse cardiovascular events against matched controls, that is an observational association in administrative data, not evidence that veins cause either outcome or that treating them prevents anything.
Often, and how often depends on the procedure. In a randomised trial followed for fourteen years, recurrent above-knee reflux occurred in 2.6 percent after high ligation and stripping, 6.1 percent after endovenous laser ablation and 30.8 percent after ultrasound-guided foam sclerotherapy, with re-intervention on the vein required in 13.2, 8.2 and 56.4 percent respectively — yet Aberdeen Varicose Vein Questionnaire scores at fourteen years were comparable across all three groups (overall P = .21).
Compression stockings help the symptoms of varicose veins and are unproven for anything else. In a randomised controlled trial of 50 patients with uncomplicated varicose veins, four weeks of class I stockings (18 to 21 mmHg) cut a symptom sum score from 8.90 to 6.37 (P = 0.004) while the untreated group did not change (7.46 to 7.67, P = 0.293), with pain, swelling and heaviness all improving — but the trial ran five weeks in total and measured symptoms only, so it shows relief and says nothing about whether stockings prevent progression, prevent ulcers, or avoid a later procedure.
The associations are real but they are not causal: in Korean national cohorts, haemorrhoidal disease carried a hazard ratio of 1.243 for all-cause dementia among 381,031 people followed a median 15.5 years, and 1.073 for heart failure among 356,033 people followed a median 13.3 years — but the authors of the dementia study state that haemorrhoidal disease may serve as a marker of an underlying systemic condition rather than directly causing dementia, and there is no mechanism by which veins at the anal canal would affect the brain or strain the heart.
Haemorrhoids after childbirth are usual, and Korean data shows childbirth is the reason the condition appears more often in women at all: among 194,620 healthy Korean adults examined by colonoscopy at a health check, the prevalence of haemorrhoidal disease was 16.6 percent overall and higher in women than men (17.2 against 16.3 percent, P < 0.001), but compared with men the prevalence was higher in women who had given birth (adjusted odds ratio 1.06, 95% CI 1.02 to 1.10) and lower in women who had not (adjusted OR 0.92, 95% CI 0.86 to 0.98).
Most people diagnosed with haemorrhoids are not operated on: in a Korean national cohort of 467,567 people followed from 2002 to 2015, haemorrhoids were diagnosed at 13.9 per 1,000 person-years and operated on at 5.7 per 1,000 person-years — roughly two surgical cases for every five diagnoses — and what predicted each was different, with a high income level associated with being diagnosed and alcohol consumption associated with being operated on.
Prior PSA testing is associated with a large difference in the treatment a man receives: among 166,848 Korean men newly registered with prostate cancer between 2010 and 2020, those with at least three PSA tests across at least two years beforehand received surgery in 45.6 percent of cases against 33.8 percent of those never tested, while hormone therapy was used in 42.3 percent of the tested group against 59.7 percent of the untested — and the untested group's higher cumulative spending came from being on systemic treatment for longer rather than from any treatment costing more per month.
On the Korean evidence it is usually not worth scanning before a PSA test: among 618 asymptomatic Korean men with a median age of 61 who had a prostate MRI at a health check-up without prior PSA testing, 9 (1.5 percent) were found to have clinically significant cancer and 57 were biopsied without finding any — and because 8 of those 9 cancers occurred in men with a PSA above 3.0 ng/mL, checking PSA first and scanning only those men would have avoided 90.0 percent of the scans, 69.9 percent of the biopsy consultations and 70.2 percent of the biopsies that found nothing, at the cost of missing one case.
Active surveillance is an option for roughly a quarter of Korean patients: among 27,075 men with biopsy-confirmed prostate cancer across 51 Korean hospitals, 6,586 (24.3 percent) were eligible under a deliberately maximised definition counting low risk, potentially low risk and favourable intermediate risk together — eligibility that fell from 27.6 percent in 2010 to 22.0 percent in 2020, and that ranged from 16.9 percent in Chungbuk to 29.3 percent in Gyeonggi — while under the narrower low-risk-only definition the figure is 5.45 percent.
A signal exists in Korean data and its cause is unresolved: in a study using electronic health records from 13 South Korean hospitals, 2,357 semaglutide initiators and 6,953 liraglutide initiators prescribed for weight loss were compared with matched non-initiators, and semaglutide was associated with psychiatric disorders overall (hazard ratio 2.02, 95% CI 1.30 to 3.14), anxiety disorder (2.39) and depressive disorder (3.42, 95% CI 1.51 to 7.74), while liraglutide was associated with psychiatric disorders (1.66), anxiety (1.68) and depression (1.51) — but the comparison group was people not taking the drug, so distress already present before starting cannot be separated out.
Most patients should not stop: consensus recommendations from the Clinical Practice Guideline Committee of the Korean Society of Anesthesiologists advise continuing GLP-1 receptor agonist therapy in most patients with individualised risk assessment, considering a 24-hour clear liquid diet before anaesthesia, and using preanaesthetic gastric ultrasound when delayed gastric emptying is suspected — while stating explicitly that current evidence is insufficient to support formally evidence-graded guidelines, so these are expert consensus rather than graded recommendations.
Summer heat does raise the risk of urinary tract infection in Korea: in a national case-crossover study covering all 4,436 emergency admissions for urinary tract infection during the summers of 2006 to 2019 among 1,131,714 insured people, a 20 percent rise in summer temperature over the preceding three days raised the odds of admission by 6 percent (odds ratio 1.06, 95% CI 1.02 to 1.10) overall, rising to 11 percent in people aged 65 or over, 12 percent in women and 14 percent in people with a history of diabetes.
Antibiotics failing in cystitis is common in Korea: in the 2023 national surveillance of 885 patients with uncomplicated cystitis, only 58.4 percent of the organisms were susceptible to ciprofloxacin — the fluoroquinolone most often prescribed first — against 94.9 percent for fosfomycin and 90.5 percent for nitrofurantoin, and fluoroquinolone resistance reached 59.8 percent among patients with recurrent cystitis and 44.9 percent among postmenopausal patients, so a course that fails is more likely to mean the wrong drug than an unusual infection.
The concern is real for one class of bladder drug and does not apply to the other: in Korean National Health Insurance data covering 2,360 patients aged 65 or over with overactive bladder and 11,676 matched patients without it, the cumulative 100-day anticholinergic cognitive burden score was 15.2 times higher in the overactive bladder group (320.1 against 21.0), 66.9 percent of that burden was attributable to the bladder medication itself in patients taking antimuscarinics alone, and mirabegron — a beta-3 agonist rather than an antimuscarinic — contributed zero anticholinergic burden.