How much water should patients with urinary tract infections (UTIs) drink?

Water Intake Recommendations for UTI Patients

For patients with recurrent UTIs who drink less than 1.5 L daily, recommend drinking an additional 1.5 L of water per day (total ~3 L/day) to reduce UTI frequency. 1

Evidence-Based Recommendations by Patient Population

Healthy Women with Recurrent UTIs

• Add 1.5 L of water daily to baseline intake for women with ≥3 UTIs per year who currently drink <1.5 L/day 1
• This intervention reduced cystitis frequency in a randomized trial of 140 women over 12 months 1
• Given the low-risk nature of increased hydration, this is reasonable to offer pending confirmatory studies 1

Spinal Cord Injured Patients

• Target 2-3 L of fluid per day unless contraindicated 1
• Adjust intake based on exercise intensity and climatic conditions 1
• Athletes who intentionally dehydrate during travel face increased UTI risk and should discuss prophylactic strategies with their physician 1

Postmenopausal Women

• Maintain adequate hydration as part of comprehensive prevention strategy 2
• Combine with other interventions like vaginal estrogen therapy, which has stronger evidence for UTI prevention 1, 2

Important Clinical Caveats

When to Exercise Caution

• Do not advise excessive fluid intake beyond 3 L/day in patients with acute infections, as increased antidiuretic hormone levels during illness reduce renal water excretion capacity 3
• Water intoxication with symptomatic hyponatraemia has been documented in patients with simple UTIs who over-consumed fluids 3
• Contraindications to increased fluid intake include heart failure, renal insufficiency, and conditions requiring fluid restriction 1

Strength of Evidence Considerations

The evidence base for increased water intake remains limited to one well-designed RCT in healthy premenopausal women 1. An observational nursing home study failed to demonstrate benefit but was underpowered 1. Despite limited evidence, the 2024 JAMA Network Open guidelines classify this as "clinical review" level rather than "clear recommendation" 1.

Practical Implementation

During Acute UTI Episodes

• Ensure adequate hydration (2-2.5 L/day) to support antimicrobial therapy 1
• Increase bladder emptying frequency to lower bladder pressure 1
• Adequate hydration may improve antimicrobial therapy results 4

For Prevention

• The intervention is most effective when baseline fluid intake is low (<1.5 L/day) 1
• Combine hydration with other evidence-based strategies: cranberry products (36 mg proanthocyanidins), vaginal estrogen for postmenopausal women, or methenamine hippurate 1
• Hydration alone showed 54% reduction in UTI rate at ≤6 months, though this was not statistically significant at 12 months 5

Monitoring and Adjustment

• Counsel patients on signs of overhydration (confusion, nausea, headache) 3
• Adjust recommendations based on comorbidities, medications, and individual tolerance 1
• Consider that increased fluid intake reduces overall UTI recurrence rate by 46% when adequate volumes (>200 mL increases) are consumed 5