Background: Hypertension affects over 1.4 billion adults worldwide and is among the most prevalent comorbidities in patients presenting for extracorporeal shock wave lithotripsy (ESWL). The relationship between ESWL and hypertension is bidirectional and clinically consequential. Hypertension is an established patient-level risk factor for post-ESWL renal hemorrhage, driven by hypertension-induced vascular changes — arteriolar hyalinosis, reduced vascular elasticity, and impaired autoregulation — that render renal parenchymal vessels more susceptible to shock wave cavitation forces. Conversely, a substantial body of literature has investigated whether ESWL itself may induce or worsen hypertension in previously normotensive patients through renal parenchymal scarring, renin-angiotensin-aldosterone system activation, and cumulative vascular trauma — a question that has generated significant and at times conflicting evidence over four decades of lithotripsy practice.

Objectives: This article reviews the current evidence on both dimensions of the ESWL–hypertension relationship and translates that evidence into practical pre-treatment, intraoperative, and post-treatment recommendations. It addresses the independent contribution of hypertension to post-ESWL hematoma risk, the epidemiological and mechanistic evidence on ESWL-induced new-onset hypertension, the dissenting prospective trial data, and a structured clinical protocol for safe ESWL practice in the hypertensive patient.

Methods: A structured narrative review was conducted incorporating large retrospective and cohort analyses of post-ESWL hematoma risk, prospective randomized controlled trials on ESWL-induced blood pressure changes, population-based epidemiological studies, and experimental mechanistic data. Key sources include the Skolarikos et al. analysis of 10,887 treatment episodes in 6,177 patients identifying hypertension as a significant hematoma predictor (p = 0.022); the Fernández-Arjona series of 21,699 lithotripsies confirming hypertension as one of three principal risk factors; a 2024 post-hoc analysis of two RCTs in 573 patients with systematic Day 2 cross-sectional imaging (Int Urol Nephrol 2024); the Taiwan National Health Insurance Research Database population-based cohort of 20,219 patients comparing SWL versus ureteroscopy outcomes over a median 74.9-month follow-up (Hypertension 2018); the Keeley et al. randomized controlled trial of 228 patients with small calyceal stones (BJU Int 2001); and the Indiana University experimental work of Evan, McAteer, and Connors on shock wave rate and renal injury (BJU Int 2007).

Results: Hypertension is a consistent independent predictor of post-ESWL renal hematoma across multiple large series: 50% of hematoma patients in the Skolarikos cohort and 46% in the Fernández-Arjona series were hypertensive, representing marked over-representation relative to cohort prevalence. The 2024 post-hoc RCT analysis — which identified imaging-detected hematoma in 30.9% of patients with systematic Day 2 CT — found that 44.5% of the cohort had hypertension, while emphasizing that uncontrolled hypertension, rather than its mere presence, is the key modifiable risk factor. A dissenting matched case-control analysis of 418 patients (Türk et al., PMID: 27576325) found hypertension rates not significantly different between hematoma cases and controls (p > 0.2), suggesting that adequate blood pressure control may normalize this risk. On the ESWL-induced hypertension question, the Taiwan National Health Insurance Database study found a significantly higher probability of new-onset hypertension in SWL-treated patients compared to ureteroscopy-treated patients (HR 1.20; 95% CI 1.10–1.31), with a dose-response relationship with increasing session number — the most robust epidemiological evidence of a causal signal. Three prospective RCTs including the Keeley et al. trial found no statistically significant difference in new-onset hypertension between ESWL and observation groups, highlighting an ongoing evidential tension between population-based observational data and prospective trial results. Experimentally, slowing shock wave delivery from 120 to 60 per minute significantly reduces renal injury while simultaneously improving stone fragmentation efficacy — the mechanistic foundation for rate reduction protocols in high-risk patients.

Conclusions: Uncontrolled hypertension on the day of ESWL — defined pragmatically as systolic BP > 160 mmHg or diastolic BP > 100 mmHg — is a relative contraindication; the procedure should be deferred and blood pressure optimized before proceeding. Well-controlled hypertension is not a contraindication but mandates a structured protocol modification: shock wave rate reduction to 60/min, mandatory stepwise energy ramping, a session limit of ≤ 2,000–2,500 shock waves, continuous intraoperative blood pressure monitoring, and uninterrupted perioperative antihypertensive medication. Post-procedure surveillance for hematoma — which can be asymptomatic — is mandatory, with a low threshold for renal ultrasound at 48–72 hours in symptomatic patients. For patients requiring multiple ESWL sessions, ureteroscopy should be discussed as an alternative to minimize cumulative renal parenchymal exposure and the dose-dependent new-onset hypertension risk identified in population-based data.