Most of us try not to think about dementia in our younger years. We imagine it as something that, if it must strike us, will only rear its head decades down the line when we’re already elderly and frail.

But early onset dementia, defined as dementia with symptoms that start when a sufferer is younger than 65, is on the rise.  The number of people living with it in Britain has increased by 69 per cent in the past 10 years. It’s still a relatively rare phenomenon, accounting for around 7 per cent of all cases, whereas one in 11 over-65s in Britain lives with the disease. Yet as of 2022, nearly 80,000 under-65s in this country have been diagnosed with dementia.

“Most people don’t immediately think to attribute any new health symptoms to dementia when they’re still young,” says Jan Oyebode, a professor of dementia care at the University of Bradford. It’s easy to see why. While Alzheimer’s disease accounts for most cases of dementia in older people, younger people often suffer from rarer kinds of dementia, such as frontotemporal dementia and primary progressive aphasia, which can have very different symptoms in the first instance. Memory may not be the first kind of cognitive function that changes.

“I remember one husband whose wife took a pan out of the oven without thinking to put oven gloves on first, because her impulse control was impaired,” Prof Oyebode recalls. “Another woman told me that she had sped after an ambulance because she was so excited by the flashing lights. Other people shoplift. Some even end up becoming divorced before they’re finally diagnosed. Their partners see a huge change in personality and believe that the person living with dementia no longer loves them.”

Here are the six unexpected signs of early onset dementia and what it’s possible to do about them.

1. You can’t see as well as you used to