One in 20 Ceredigion residents said they were in poor health when asked in the 2021 census, new figures show.
The data shows wide disparities in health across England and Wales, with some areas having over three times more people in bad health than others.
Health think tank the Nuffield Trust said the postcode lottery of health tracks socio-economic deprivation, and called on the government to address disparities in healthcare, provision and overall health guidance.
Office for National Statistics figures show 5.5 per cent of residents in Ceredigion said they were in "bad or very bad" general health in the 2021 census.
Nationally, 5.4 per cent of people responded to the census saying they were in bad or very bad health. This rose to 6.7 per cent in Wales.
The Nuffield Trust said people living in certain areas fair much worse than others, and that the improvement in health across the country has not been enjoyed uniformly.
There were also regional disparities in the number of unpaid carers across the country, the figures show.
In London and the South East, 4 per cent of the population said they provided at least 20 hours of unpaid care per week. At the other end of the scale, this figure rose to 5.8 per cent in Wales.
In Ceredigion, 5.2 per cent of the population said they provided high levels of unpaid care.
The data also shows 8.5 per cent of Ceredigion residents were classed as disabled in 2021.
By the ONS ranking of health levels – which takes into account poor health, disability and unpaid care – Ceredigion ranks 229th of England and Wales's 331 local authority areas.