Aging is a gradual decline in biological function driven by accumulated cellular and molecular damage. Core mechanisms include genomic instability from DNA damage, telomere shortening that limits cell divisions, and epigenetic changes that alter gene activity with age. Mitochondria, the cell’s powerhouses, become less efficient and produce more reactive oxygen species, which further damage cellular components.

Cells respond to stress and injury with repair and maintenance systems, but these become less effective over time. Senescent cells, which have permanently stopped dividing, accumulate in tissues and secrete inflammatory molecules that disrupt nearby healthy cells. This “inflammaging” is a key contributor to age related diseases such as cardiovascular disease, neurodegeneration and cancer.

Protein homeostasis also declines. Misfolded or damaged proteins are less effectively cleared and can aggregate, as seen in conditions like Alzheimer’s disease. Stem cell exhaustion reduces the body’s capacity to regenerate tissues, leading to frailty and impaired wound healing. Changes in cell communication and chronic low grade inflammation progressively disturb the balance that keeps organs functioning.

Research on aging focuses on mapping these hallmarks, understanding how they interact and testing interventions that might slow or partially reverse them. Strategies under investigation include senolytic drugs that selectively remove senescent cells, treatments that improve mitochondrial function, and approaches that reset epigenetic marks toward a more youthful state. Scientists are also studying how diet, exercise and metabolic pathways influence longevity. Together, these efforts aim not only to extend lifespan but more importantly to prolong the period of life spent in good health.