A cigarette is a small cylinder of finely cut tobacco leaves rolled in thin paper for smoking. The cigarette is ignited at one end causing the cigarette to smoulder and allowing smoke to be inhaled from the other end, which is held in or to the mouth; in some cases, a cigarette holder may be used, as well. Most modern manufactured cigarettes are filtered, and also include reconstituted tobacco and other additives.
The term cigarette, as commonly used, refers to a tobacco cigarette but can apply to similar devices containing other substances, such as a cannabis cigarette. A cigarette is distinguished from a cigar by its smaller size, use of processed leaf, and paper wrapping, which is normally white, though other colors and flavors are also available. Cigars are typically composed entirely of whole-leaf tobacco.
Rates of cigarette smoking vary widely throughout the world and have changed considerably since cigarettes were first widely used in the mid-19th century. While rates of smoking have over time leveled off or declined in the developed world, they continue to rise in developing nations.
Nicotine, the primary psychoactive chemical in tobacco and therefore cigarettes, is very addictive. About half of cigarette smokers die of tobacco-related disease and lose on average 14 years of life. Cigarette use by pregnant women has also been shown to cause birth defects, including low birth weight, fetal abnormalities, and premature birth. Second-hand smoke from cigarettes has been shown to be injurious to bystanders, which has led to legislation that has prohibited smoking in many workplaces and public areas. The smoke produced is an aerosol containing over 4,000 distinct chemical compounds, including nicotine, carbon monoxide and acrolein. Over 50 of these are carcinogenic. Cigarettes are a frequent source of house fires, which prompted both the European Union and the United States to ban cigarettes that are not fire-standard compliant from 2011 onwards.