One of the easiest ways to make yourself unfit, and to make your lungs and heart work less well, is to smoke cigarettes The World Health Organization estimates that, each year: 4.2 million people will die carly as a result of smoking cigarettes cigarettes kill half of all the people who smoke them regularly smoking kills more people each year than a the deaths from IIIV/AIDS, drugs and road accidents added together. People who do not smoke cigarettes themselves may get ill if they breathe in other people's cigarette smoke. Children are especially at risk, if adults in their home regularly smoke cigarettes.