In arid regions, groundwater contamination poses a critical threat to public health and agricultural sustainability. This study presents an integrated assessment of groundwater quality, hydrogeochemical processes, and associated health risks in five key districts (Bolan, Kalat, Nasirabad, Pishin, and Qilla Abdullah) of the water-stressed Baluchistan province, Pakistan. A total of 188 groundwater samples were analyzed for 16 physicochemical parameters. The Groundwater Quality Index (GWQI) classified water as "Poor" to "Unsuitable" in 60.0%, 59.0%, and 47.8% of samples from Nasirabad, Qilla Abdullah, and Bolan, respectively. Hydrochemical analysis, supported by Piper diagrams and ionic indices, indicated that groundwater in the study area is primarily dominated by Na-Cl, Na-HCO3, and mixed Ca-Mg-Cl facies, reflecting rock-water interactions, silicate and carbonate weathering, and spatially variable cation exchange processes. Irrigation suitability assessment, based on indices like Potential Salinity and Magnesium Hazard, revealed a high risk of salinity and magnesium hazard in most districts, threatening agricultural sustainability. The Health Risk Assessment model showed that fluoride exposure via ingestion poses a significant non-carcinogenic risk to the local population, with children being the most vulnerable group. Hazard Index (HI) values exceeding the safe threshold were observed in 97.1% of the population in Nasirabad and over 82% in Bolan. This comprehensive analysis underscores the urgent need for targeted mitigation strategies and sustainable groundwater management policies in this arid region.