Most avid smokers lull themselves into the belief that they have quit smoking, even if they have reduced their smoking drastically to just one cigarette a day.
However, the survey by Co-operative Pharmacy revealed more than half (57 per cent) of smokers keep their habit a secret from family and friends, and most often from their partner, the Daily Mail reported.
When smokers sneak out for a cigarette, they are most likely to say they are going to the shop, to see a friend or to walk the dog.
Additionally a study from the National Health Screening Service in Oslo, Norway, found 'light' smokers were three times more likely to die of lung cancer than non-smokers.
The survey of 2,000 smokers revealed that nearly 80 per cent of smokers want to quit although a third said that they have smoked less since the smoking ban in public places was implemented in 2007.
About one in 12 are also barred from smoking in their own home.
"The smoking ban in public places has had a major effect on the health of the nation with a significant number of people giving up, but many smokers now try to keep their habit secret from their partner, children, friends and family," Fiona Caplan-Dean, clinical services manager at the Co-operative Pharmacy, which carried out the survey, said.
"Light smokers in particular convince themselves that they have quit but still smoke.
"Just smoking one or two cigarettes a day has an impact on health and is detrimental to your skin and appearance," Caplan-Dean added.