New research led by the University College London and the University of Cambridge is the first to show that being confused or disoriented can cause brain functionality to decline at a rapid rate.
Delirium affects roughly a quarter of elderly people and can cause confusion, panic and distress.
They then linked the study to hospital stays, as these carry an element of confusion and upset in a busy and unfamiliar environment.
The researchers found that Elderly patients diagnosed with delirium were eight times more likely to be diagnosed with dementia within the following three years after a hospital stay.
While hospital stay are not the cause of the onset of dementia, extended periods of hospitalisation can contribute to the decline of the individual.
Dr Clare Walton from the Alzheimer's society said: "Delirium is quite common among older people, especially among older people, especially those in hospital or living with dementia. Growing evidence shows that a case of delirium can predict worsening memory and thinking problems or the onset of dementia."
Future research will look at the long-term impact of delirium on the brain and this could help to understand brain function and dementia better.
All information from the Daily Mail.