According to the World Health Organization, deaths from dementia have doubled since 2000 and dementia is now the fifth biggest killer worldwide.
But dementia has already claimed number one spot in some richer countries.
In England and Wales, one in eight death certificates cite dementia.
There is also a key difference with other major killers such as cancer or heart disease, because there is not a single treatment that either cures or slows the pace of any dementia.
“Dementia certainly is the biggest health challenge of our time,” Hilary Evans, chief executive of the charity Alzheimer’s Research UK, told the BBC.
“It’s the one that will continue to rise in terms of prevalence, unless we can do something to stop or cure this disease.”