Stoptober: You can see the benefits of quitting smoking after 20 minutes, experts reveal

After eight hours, your oxygen levels will start to recover. In fact, the harmful carbon monoxide levels in your blood will have reduced by half, according to the NHS.After eight hours, your oxygen levels will start to recover. In fact, the harmful carbon monoxide levels in your blood will have reduced by half, according to the NHS.Read MoreHealth News | Mail Online