Dementia is fast becoming one of the leading causes of death in the developed world. A better understanding of the impact of dementia on physical health is necessary to prevent illness leading to disability and dependence. Dementia can have a direct effect on eating, apathy, continence and mobility as a consequence of the disease process centrally. In addition, dementia can have a secondary health impact through falls, immobility and dementia medication side effects. Dementia is very much a disease that rises in frequency with age. Other common co-morbidities become more frequent also and overlap. This requires multidisciplinary expertise to address acute illness in a patient centred fashion. Physical illness and frailty (age related vulnerability to adverse outcomes) can lead to an increased risk of delirium and adverse cognitive outcomes. Medication for the management of physical conditions may have anti-cholinergic side effects that can worsen cognition. Surgery also carries a greater risk for patients with dementia. Dementia is under recognised as a disease with physical effects requiring expert multidisciplinary care.