Climate change represents one of the most significant global health challenges of the twenty-first century, affecting every population through direct and indirect pathways. The primary drivers include rising greenhouse gas emissions from human activities such as fossil fuel combustion, deforestation, and industrialization, leading to global warming and extreme weather patterns. The impact of climate change on existing health issues and new threats through heatwaves, air pollution, vector-borne diseases, waterborne infections, food insecurity, and mental health disorders has been discussed here. Vulnerable populations, including children, the elderly, individuals with pre-existing conditions, and those in low-income communities, are disproportionately affected. Global and region-specific examples, such as the heatwave fatalities in India and waterborne disease outbreaks in the USA and West Bengal, support the narrative. The chapter also discusses the link between climate-induced migration and psychosocial stress. Urgent and coordinated action at global, national, and local levels is emphasized to mitigate these impacts and protect public health.