A cigarette is a narrow cylinder containing a combustible material, typically tobacco, that is rolled into thin paper for smoking. The cigarette is ignited at one end, causing it to smolder; the resulting smoke is orally inhaled via the opposite end. Cigarette smoking is the most common method of tobacco consumption. The term cigarette, as commonly used, refers to a tobacco cigarette, but the word is sometimes used to refer to other substances, such as a cannabis cigarette or an herbal cigarette. A cigarette is distinguished from a cigar by its usually smaller size, use of processed leaf, and paper wrapping, which is typically white. Since the 1920s, cigarettes have been a major source of advertising revenue for the media, of traffic for small stores, and of tax revenue for governments.
Since the 1920s, scientists and doctors have been able to link smoking with respiratory illness. Researchers have identified negative health effects from smoking cigarettes such as cancer, chronic obstructive pulmonary disease (COPD), heart disease, and other health problems relating to nearly every organ of the body. Nicotine, the psychoactive drug in tobacco, makes cigarettes highly addictive. About half of cigarette smokers die of tobacco-related disease and lose on average 14 years of life. Every year, tobacco cigarettes kill more than 8 million people worldwide; with 1.2 million of those being non-smokers dying as the result of exposure to second-hand smoke. Second-hand smoke from cigarettes causes many of the same health problems as smoking, including cancer, which has led to legislation and policy that has prohibited smoking in many workplaces and public areas. Cigarette smoke contains over 7,000 chemical compounds, including arsenic, formaldehyde, hydrogen cyanide, lead, carbon monoxide, acrolein, and other poisonous substances. Over 70 of these are carcinogenic. Most modern cigarettes are filtered, although this does not make the smoke inhaled from them contain fewer carcinogens and harmful chemicals.