Whether it is family or friends, neighbours or work colleagues, the chances are we all know someone who is affected.
And bearing in mind the figure leaves out less common conditions and is a snapshot in time, you could easily argue it is even more prevalent than that. Indeed many do.
With Prime Minister Theresa May expected to announce plans to improve care next week, these 10 charts show the extent of the challenge. Continue reading.
Originally posted on BBC News/Health.