This document is an introduction to a collection of reviews on ageing research. It summarizes that ageing leads to decline and increased risk of disease. Research has found that single gene mutations can substantially extend the lifespans of various organisms from yeast to mice and delay age-related diseases. Many of these pathways are conserved in humans, offering hope that this research could benefit human health. As more people are living longer, finding ways to keep the elderly healthy and suppress the effects of ageing itself is a high priority.