One in 23 people aged 65 and over in England is diagnosed with dementia, according to new figures.
The data, collected from 98% of GP practices, shows that in 2016/17 422,000 people over the age of 65 were recorded as having the disorder.
Dementia is most common in women aged 90 and over, with one in five having the condition.
However, many more people are thought to have dementia but have not been diagnosed.
The report from NHS Digital also showed that 207,797 people aged 65 and over were admitted to hospital in an emergency with a diagnosis of dementia.