A cigarette, also known colloquially as a fag in British English, is a narrow cylinder containing psychoactive material, usually tobacco, that is rolled into thin paper for smoking. Most cigarettes contain a "reconstituted tobacco" product known as "sheet", which consists of "recycled [tobacco] stems, stalks, scraps, collected dust, and floor sweepings", to which are added glue, chemicals and fillers; the product is then sprayed with nicotine that was extracted from the tobacco scraps, and shaped into curls. The cigarette is ignited at one end, causing it to smolder; the resulting smoke is orally inhaled via the opposite end. Most modern cigarettes are filtered, although this does not decrease health risks associated with smoking. Cigarette manufacturers have described cigarettes as a drug administration system for the delivery of nicotine in acceptable and attractive form. Cigarettes are addictive and cause cancer, chronic obstructive pulmonary disease, heart disease, and other health problems.