‘Physical and biological aspects of ageing’ considers influences on longevity and the physical disorders commonly experienced at the end of life. It describes primary and secondary ageing and different biological theories of ageing—error and programme theories. Error theories (e.g. wear and tear theory, free radical theory, and somatic DNA damage theory) postulate that ageing and death are the result of environmental damage to the body over time. Programme theories (e.g. endocrine theory, immunological theory, and genetic theory (programmed longevity)) postulate that lifelong growth and development is genetically programmed to follow a pre-determined timeline. The ageing brain and body, and disease trajectories later in life are also considered.