China, in short:
…health costs will rise more rapidly as a percentage of national income among Third World nations that are now entering into modern economic growth than has been the case in OECD countries…
The supply of chronic conditions that require treatment is much greater at middle and late ages in China than the supply that currently exists in OECD nations…a [previous] low life expectancy and such a high infant death rate mean that those who survived to middle ages experienced severe biomedical and socioeconomic insults in utero, in infancy, and in later developmental stages…Despite the rapid advances in public health and strong economic growth, the negative conditions that influenced physiological development remained severe into the early 1960s…such early-life insults reduce the waiting time to the onset of chronic diseases at later ages and increase their severity.
Consequently, individuals who are age 50 and older in China today will have far higher prevalence rates of chronic diseases than is the case in OECD nations.
That is all from Robert Fogel’s short but excellent The Escape from Hunger and Premature Death, 1700-2100.
It is estimated that the number of chronic diseases per person could be triple than currently experienced in the United States; the level in China would be comparable to that of the U.S. in about 1900. At that time the average American male suffered from six chronic medical conditions, and it was very likely that at least one of those six was debilitating, meaning the person could not work.
The bottom line: Expect China to experience some serious demographic problems in the coming decades.