The number of patients addicted to opioid painkillers in England and the length of time they have been dependent will be set out in full for the first time in a major report due out in weeks.
Sources say the report from Public Health England will serve as a "wake-up call" on the extent of opioid dependency.
While noting there is nothing yet on the scale of the opioid addiction crisis in North America, they say the report will highlight areas of concern including higher numbers of patients on the drugs in more economically deprived areas.
A recent report by the Organisation for Economic Co-Operation and Development examined the issue in 25 wealthier nations.
It noted that while the UK was below countries like the US and Germany for the volume of legally available opioids, it had seen one of the fastest rates of growth over three years to 2016.
The Public Health England report will consider both over-the-counter and prescription opioid painkillers, such as morphine, tramadol, fentanyl and codeine.
It will be the first comprehensive analysis of the number of patients with long-term dependency. Differing prescribing levels around the country and varied approaches by GPs will be considered.
Sherry Flatt has been on and off opioid painkillers for more than 20 years, following back injuries and other problems.
In an interview for the BBC's Ten O'Clock News she said: "I was in a lot of pain. The pain started in my spine. Over time I knew I was addicted to them. They knew I was addicted to them."
At times, she says, she struggled to leave the house and her mind was a constant blur: "It kept me trapped, really. There were no life - I was just existing. I didn't have a life… I just didn't think I could live it."
But thanks to counselling and support from a specialist addiction service in Bradford, New Directions, she has managed to cut her daily dose by two thirds and now feels confident enough to go out to the shops and plan a holiday.
Nicki Hari is now an admissions coordinator with the UK Addictions Treatment Group. She successfully got through a rehab programme after 20 years or so of dependency.
She first took opioid painkillers after a knee operation, but it was only years later that she realised she was addicted.
"I didn't know what addiction was. I knew there were people addicted to alcohol and heroin - but that wasn't me," she said.
"I'm a middle class mum that had a family, a nice house, a nice car - but things just became worse and worse. If I didn't have it I would go into a real panic."
The role of GPs and their prescribing habits is an important part of the opioid debate.
Difficult decisions have to be made in often brief appointments, and it can be hard to refuse repeat prescriptions if patients say they have continuing pain.
There is limited time to explore underlying health conditions.
Dr Cathy Stannard, a consultant in pain medicine, holds workshops for GPs to discuss all the issues and explore options. One of her main messages is that opioid painkillers rarely work for patients.
"Fewer than one in 10 people that are taking them for pain will experience a reduction in pain.
"They are on a medicine that's not helping but they are on a medicine that's causing many harms."
Opioid painkiller use and abuse is an international problem. Public Health England's report will try to set out the extent of the challenge for the NHS and patients - then it will be up to policymakers to seek solutions.
Watch Hugh Pym's full report on the Ten O'Clock News on BBC iPlayer.