More than two million people in the UK are classed as problem or at-risk gamblers, according to new research.
Data compiled by the Gambling Commission - the body that regulates and licences the gambling industry in the UK - found that 63% of British adults had gambled in the past year.
The report found that 1.4% of gamblers, 400,000 people were classed as problem gamblers - or 0.8% of the population.
A further 6.4% of gamblers are deemed to be at-risk, a total of 3.9% of the population.
Problem and at-risk gambling habits were found at much higher levels in solitary gambling activities, such as online gambling sites.
Online casinos, slot machines and bingo accounted was a draw for 34.9% of people with a chronic or worrying gambling habit, followed by betting machines at 31.7%.
Spread betting was a draw for 28.7% of problem and at-risk gamblers.
Lotteries and scratch cards were the lowest risk, with only 6% of at-risk gamblers playing the National Lottery, followed by 10.6% for scratch card and 6.4% on other lotteries.
The research also found that the more different gambling activities an individual participated in, the higher their risk of becoming addicted.
Among people participating in seven or more different types of gambling, 26.1% were problem or at-risk gamblers.
Unemployment was found to be one of the biggest factors influencing gambling habits, with 10.1% of problem and at risk gamblers without work.
Only 4.6% of those with a gambling issue were found to be in employment, self-employed or in full-time government training.
Levels of worrying gambling behaviour were lowest in retired people, with only 1% of retirees found to be at risk or to have a gambling addiction.
The figures have sparked calls for the government to do more to try and tackle problem gambling, not just for the sake of the individuals involved but for those affected by their behaviour.
Tim Miller, executive director of the Gambling Commission, said: "We have a clear commitment to make gambling fairer and safer and these figures show that this is a significant challenge.
"Success will depend upon us, the industry, government and others, all working together with a shared purpose to protect consumers.
"The pace of change to date simply hasn't been fast enough- more needs to be done to address problem gambling."
The report comes in the wake of the government's decision to delay a report into Fixed Odd Betting terminals - dubbed the "crack cocaine" of betting.
The machines allow punters to stake - and lose - £100 every 20 seconds.
There have been calls to limit the stakes to a maximum of just £2 and a review had been due in June but has been delayed until the autumn.