This proportion is likely to rise as the population ages, researchers wrote in the study published in journal BMJ Open, adding that chronic pain is a major cause of disability and distress among those affected by it.
The researchers trawled relevant databases to find studies on different types of pain, published after 1990.
The search included studies on population based estimates of chronic pain - defined as lasting more than three months - chronic widespread pain, fibromyalgia (a rheumatic condition characterised by muscular or musculoskeletal pain), and chronic neuropathic pain (pain caused by nerve signalling problems).
Researchers pooled the study data to arrive at an estimate of the prevalence of chronic pain, overall and chronic widespread pain.
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Summary estimates were also drawn up for moderate to severely disabling chronic pain, fibromyalgia and chronic neuropathic pain among UK adults.
Based on seven studies, the researchers worked out that the prevalence of chronic pain ranged from 35 per cent to 51 per cent of the adult population, with the prevalence of moderate to severely disabling chronic pain, ranging from 10 to 14 per cent - equivalent to around 8 million people.
The summarised data also showed that 8 per cent of UK adults experience chronic neuropathic pain, and 5.5 per cent live with fibromyalgia.
Twelve of the studies categorised the prevalence of pain by age group, and these showed that older people were more likely to live with pain over the long term.
Among 18-25 year olds, the prevalence was 14 per cent, although it may be as high as 30 per cent among 18-39 year olds, the analysis indicates - a sizeable chunk of the working population, researchers said.
Women were more likely than men to be affected by chronic pain, irrespective of age or pain type.
The researchers point out that the included studies varied considerably, and that not all of them were of high quality, making it difficult to draw firm conclusions.
The studies showed gradually increasing prevalence of chronic pain over time, from 1990. The researchers estimate that the prevalence of chronic pain in the UK is now around 43 per cent, equating to around 28 million people, based on population stats for 2013.