Tobacco smoking is the inhalation of smoke from burned dried or cured leaves of the tobacco plant, most often in the form of a cigarette. People may smoke casually for pleasure, habitually to satisfy an addiction to the nicotine present in tobacco and to the act of smoking, or in response to social pressure. In some societies, people smoke for ritualistic purposes. According to the WHO about one-third of the world's male population smokes tobacco.Tobacco use by Native Americans throughout North and South America dates back to 2000 BC. The practice was brought back to Europe by the crew of Christopher Columbus. Tobacco smoking took hold in Spain and then was introduced to the rest of the world by trade. Tobacco is an agricultural product processed from the fresh leaves of plants in the genus Nicotiana. Tobacco has been growing on the northern continents since about 6000 BC and began being used by native cultures at about 3000 BC. It has been smoked in one form or another since about 2000 BC. There are pictoral drawings of ancient Mayans smoking crude cigars from 1400 BC.
Tobacco smoke contains nicotine and harmane (a MAO inhibitor), which combined give rise to addictive stimulant and euphoriant properties. The effect of nicotine in first time or irregular users is an increase in alertness and memory, and mild euphoria. Nicotine also disturbs metabolism and suppresses appetite. This is because nicotine, like many stimulants, temporarily increases blood sugar levels.
Medical research has determined that tobacco smoking causes lung cancer, emphysema, and cardiovascular disease among other health problems.The World Health Organization reported that tobacco smoking killed 100 million people worldwide in the 20th century and warned that it could kill one billion people around the world in the 21st century

Through this forum I came to know about the hazardous diseases caused by smoking tobacco.Earlier i was unaware that smoking is being done since 1400 BC, its shocking to hear that,100 million peoples were killed worldwide in the 20th century.I was shocked to hear that 0ne Billion people can be killed due to smoking in 21st century.Please keep on posting about such informative health issues.
_____________________________________________________
Stephen