A brain disease characterised by cognitive disorders (e.g. reduced memory, mental capacity or recognition of objects or faces). It is a complex of symptoms with a variety of possible causes. The most common form of dementia is Alzheimer’s disease (ICD-10 code G30); this accounts for half of all cases. Other forms are for example vascular or frontotemporal dementia. When there is no identifiable cause it is referred to as demential syndrome ((ICD-10 codes: F01-F03, F05) and the cause of death is classified under psychiatric disorders (Chapter F of the ICD-10). When there is an identifiable cause or specific form,  the cause of death is classified under diseases of the nervous system (Chapter G of the ICD-10). For tabulation of dementia as death cause, ICD-10 codes F01-F03, F05 and G30 are used. A new version of the ICD will end this dispersion of information over several different chapters. 
People die from the consequences of dementia, e.g. stopping intake of food or drink, swallowing difficulties or infections because in advanced dementia, brainstem reflexes such as swallowing, breathing (reduced continuation of breathing, resulting in pneumonia) or the bladder reflex (with incontinence as a result) no longer function properly. Therefore, statistics on death causes consider dementia to be the underlying cause of death.