Cigarette smoking is a highly addictive activity practiced by millions of U.S. adults and teenagers. Doctors and public health officials commonly try to identify smokers as part of an ongoing effort to prevent the severe health complications that often accompany cigarette use and nicotine addiction. However, according to the results of a study published in February 2014 in the journal Tobacco Control, a significant percentage of people who smoke cigarettes do not consider themselves to be \u201csmokers,\u201d even when they use tobacco\/nicotine on a daily basis. The Basics The popularity of cigarette smoking has been in decline in the U.S. for decades. Despite this fact, roughly 19 percent of American adults still smoke. In gender terms, men are substantially more likely to smoke than women (21.6 percent vs. 16.5 percent). In terms of age, the highest rate of acknowledged smoking (22.1 percent) occurs in people between their mid-20s and mid-40s. In racial\/ethnic terms, the highest rates of acknowledged smoking occur in non-Hispanic American Indian\/Alaska natives (31.5 percent) and non-Hispanic whites (20.6 percent). In educational terms, people who receive a GED equivalency degree smoke much more often than any other group, including those who never finished high school or received a GED degree. In addition, people who officially live in poverty smoke substantially more often than people who border on poverty or whose income places them above the poverty line. Addiction and Physical Illness Like other addictive substances, nicotine produces its impact because it triggers long-term changes in the brain\u2019s chemical environment when used regularly over time. However, unlike most other addictive substances, nicotine itself does not typically present a serious risk to human health and well-being. Instead, the vast majority of harm associated with nicotine\/tobacco use comes from exposure to the dozens of known illness-producing chemicals contained in various tobacco products. Figures provided in early 2014 by the Centers for Disease Control and Prevention indicate that roughly 20 percent of all yearly deaths in the U.S. stem from smoking-related illnesses. Prominent examples of these conditions include chronic obstructive pulmonary disease or COPD (emphysema and chronic bronchitis), coronary heart disease, heart attacks, strokes, lung cancer and cancer in a range of other organ systems throughout the body. Additional significant problems clearly linked to cigarette use include type 2 diabetes, rheumatoid arthritis, declining tooth and gum health, pregnancy complications and increased risks for osteoporosis in post-menopausal women. \u201cNon-Smoking\u201d Smokers In the study published in Tobacco Control, researchers from the University of California, San Diego used data from a large-scale project called the 2011 California Longitudinal Smokers Survey to estimate the number of adults in the general population who smoke cigarettes but don\u2019t identify themselves as \u201csmokers.\u201d The researchers used several criteria to identify these individuals, including intake of at least five packs of cigarettes at any point in time, participation in at least one incidence of smoking in the month prior to the survey and use of cigarettes on at least an occasional basis. Slightly less than 396,000 participants in the survey met the researchers\u2019 criteria for smokers who don\u2019t consider themselves to be smokers. This figure represented just over 12 percent of all cigarette users involved in the survey. Critically, nearly 22 percent of those who failed to identify themselves as smokers used cigarettes on a daily basis. The researchers concluded that adults who smoke but don\u2019t consider themselves smokers generally fall into one of two groups. One of these groups includes younger adults who only or mainly smoke in social settings such as bars or parties, and therefore tend not to believe that they could suffer the effects of nicotine addiction. The second group includes older adults who previously self-identified as smokers but subsequently participated in smoking cessation efforts that curbed, but did not eliminate, their nicotine\/tobacco intake. The individuals in this second group are likely motivated, at least in part, by a desire to avoid any social stigma associated with ongoing cigarette use. Significance and Considerations The authors of the study published in Tobacco Control believe their findings show that cigarette smoking \u201cnon-smokers\u201d are much more common than previously thought. If they\u2019re correct, millions of people across the country may have significant but unacknowledged risks for developing a serious or potentially fatal tobacco-related illness. The study\u2019s authors also believe that public health efforts to gauge the number of people who smoke must include methods to identify smoking \u201cnon-smokers\u201d in order to accurately reflect larger smoking trends and help provide the appropriate interventions and treatments for affected individuals.