Most of the DNA in the human genome does not encode proteins but is involved in regulatory functions. In addition, the human genome is characterized by an extensive array of structural DNA variants arising from de novo mutations plus accumulated structural variants transmitted through an individual's lineage. The result is that each person has a unique genome which is expressed as that person's unique phenotype. Ageing can be understood on both the species and individual level. Each species has a programmed ageing and mortality pattern, but within those broad species-specific boundaries there is considerable individual variation. At the individual level, ageing reflects the integrated effects of that individual's unique mix of DNA structural variants, unique experience-specific epigenetic marks and imperfectly repaired genomic and cellular damage. This book examines human "chronic degenerative" diseases which are not diseases, but rather variations of the ageing process across individuals.