The article discusses the role of cellular senescence in aging and age-related diseases, highlighting its potential as a therapeutic target. Senescence, a process that arrests cells in the cell cycle in response to stressors, has been linked to both beneficial and detrimental effects. The authors review the current understanding of senescence in cultured cells and living organisms, emphasizing the challenges in identifying and characterizing senescent cells in tissues and organs. They explore the stressors that induce senescence, the cell types prone to senescence, and the autocrine and paracrine properties of senescent cells in aging and age-related diseases. The article also delves into the impact of senescence on human health, including its role in normal aging, age-related diseases, and therapeutic interventions. It discusses the potential benefits and drawbacks of targeting senescent cells, such as the clearance of preneoplastic cells and the clearance of senescent cells in wound repair and embryogenesis. The authors propose a framework for understanding the causes and roles of senescent cells in chronic disease and aging, and they highlight the need for further research to address unresolved questions in the field.The article discusses the role of cellular senescence in aging and age-related diseases, highlighting its potential as a therapeutic target. Senescence, a process that arrests cells in the cell cycle in response to stressors, has been linked to both beneficial and detrimental effects. The authors review the current understanding of senescence in cultured cells and living organisms, emphasizing the challenges in identifying and characterizing senescent cells in tissues and organs. They explore the stressors that induce senescence, the cell types prone to senescence, and the autocrine and paracrine properties of senescent cells in aging and age-related diseases. The article also delves into the impact of senescence on human health, including its role in normal aging, age-related diseases, and therapeutic interventions. It discusses the potential benefits and drawbacks of targeting senescent cells, such as the clearance of preneoplastic cells and the clearance of senescent cells in wound repair and embryogenesis. The authors propose a framework for understanding the causes and roles of senescent cells in chronic disease and aging, and they highlight the need for further research to address unresolved questions in the field.