Caring for a person with Alzheimer's disease can cause emotional, psychological and physical problems. In most cases of Alzheimer's disease, at least two individuals are affected: the person with the condition and the caregiver. This article is the first of two about Alzheimer's disease and its effect on informal carers. The first discusses the literature that relates to the physical and psychological effects of caring for a person with Alzheimer's in the home. The second article summarises a quantitative study of 42 caregivers in the west of Ireland, and the physical and psychological effects of the caregiving role on them.