Smoking remains the biggest cause of preventable illness and early death in the UK. One in five adults in the UK (about 10 million people) are smokers and second-hand exposure to smoke in the home affects an estimated five million children under the age of 16. Unemployed people (i.e. those not working but seeking work) are around twice as likely to smoke as those who are either in employment or economically inactive (e.g. students or retired people).

Regions in the north of England and Scotland have the highest proportions of smokers in the UK. In the 50 or so years since a causal link between lung cancer and smoking was first established, there has been a decrease in smoking prevalence. This has been achieved through a combination of tobacco control measures and the development of stop smoking services and treatments for smokers who want to quit.

About 67 per cent of people who smoke say they would like to stop. In the year from April 2013 to March 2014, around half a million people had set a quit date through the NHS Stop Smoking Service in England and around half had successfully quit at a four-week follow-up, mainly with the use of smoking cessation therapies. However, the number of people giving up smoking has been gradually falling in recent years and this has prompted the introduction of harm reduction approaches.