A silent epidemic is spreading across India rural heartlands one that links rising heat, extreme working conditions, and failing kidneys. Chronic kidney disease of unknown origin (CKDu) is claiming lives and livelihoods, particularly among outdoor laborers who toil for hours in blistering temperatures without adequate water, shade, or rest.
Arumugam, a 64-year-old salt pan worker from Tamil Nadu’s Villipakam village, spends four hours twice a week on dialysis after his kidneys failed six years ago. Like many in his village, he began working in salt pans as a teenager, enduring heat that often crossed 40°C with little water or rest. The long exposure to heat and dehydration has taken its toll, leaving him weak and heavily indebted from his treatment costs.
Across India, similar stories are emerging men in their 30s and 40s from farming, construction, and sanitation sectors developing severe kidney damage without the usual causes like diabetes or hypertension. Doctors say the condition is becoming increasingly common, and many rural communities lack proper diagnosis or treatment facilities.
Studies from Andhra Pradesh’s Uddanam region, a known hotspot, suggest that between 40 to 60 percent of its population may be affected by CKDu. Research points to prolonged heat exposure, dehydration, and strenuous labor as major culprits. A 2020 study in Tamil Nadu found that 90 percent of salt pan workers were exposed to unsafe heat levels, while their water intake was barely one liter in an eight-hour shift far below the recommended amount. In Odisha, another study linked 14 percent of farming communities’ kidney damage to heat stress.
Scientists warn that climate change is worsening this health crisis. As global temperatures rise India faces longer, harsher heat waves that threaten outdoor workers’ health and productivity. Experts say kidney damage from heat builds slowly daily dehydration leads to acute injuries that, over years, evolve into chronic kidney disease.
Researchers like Vidhya Venugopal from Sri Ramachandra Institute and Jason Glaser from the La Isla Network stress that the disease is not just medical it’s social. Poor labor protections, lack of rest breaks, and payment systems that reward nonstop work push laborers to the brink. Glaser notes that when workers are given rest, shade, and water, both productivity and health outcomes improve benefits that ultimately save governments money by reducing healthcare costs.
India offers free dialysis to poor patients but public health facilities are overwhelmed. With no national registry to track CKDu cases, the true scale remains unknown. Experts fear that unless preventive steps are taken, CKDu could become one of India’s largest health crises in coming decades.
“Kidneys are the canary in the coal mine,” says nephrologist Vivekanand Jha of the George Institute for Global Health. “They’re warning us about the human cost of climate change.”
Preventing CKDu researchers emphasize, requires simple but essential measures: access to clean drinking water, shaded rest areas, and hourly breaks. Without these, India’s most vulnerable workers already burdened by poverty and inequity will continue paying the highest price for a warming planet.