Mumbai summer health check-ups show increased acidic urine, low iron, study finds

A recent analysis of routine health check-up data by Plum Health Insurance has revealed that summer in Mumbai affects residents differently than in other Indian cities, with notable changes in certain blood and urine markers.

The study compared health check-ups conducted during the summer months of April and May 2026 with those from the winter period of November 2025 to February 2026. It found that Mumbai's strongest summer signals were not the classic markers of dehydration seen in hot and dry regions, such as concentrated urine. Instead, patients in Mumbai showed a significant increase in acidic urine, low iron levels, and lower haematocrit during summer.

Specifically, the share of patients with acidic urine rose by 32 per cent, low iron by 63 per cent, and low haematocrit by 38 per cent compared to winter. Meanwhile, concentrated urine, a common indicator of dehydration, actually fell by 9 per cent. The analysis covered 1,382 patients from the Mumbai metropolitan region, including Thane and Navi Mumbai.

These findings suggest that the humid coastal climate of Mumbai may lead to distinct physiological responses, different from those in dry-heat cities. Experts note that while dry heat often leads to higher urine concentration due to dehydration, humidity can affect blood markers and urine acidity more prominently. The study highlights the need for region-specific health advisories during extreme weather conditions.

Plum Health Insurance, which provides health insurance and wellness services, conducted the analysis based on their policyholders' check-up data. The results underscore the importance of understanding local environmental impacts on health, especially in the context of rising temperatures due to climate change.