Smoking is a practice where a substance, most commonly tobacco, is burned and the smoke tasted or inhaled. This is primarily done as a form of recreational drug use, as combustion releases the active substances in drugs such as nicotine and makes them available for absorption through the lungs. It can also be done as a part of rituals, to induce trances and spiritual enlightenment.

Health warnings on Australian tobacco products have been mandated through federal legislation since 1973, being updated in 1987 and 1995. Issue of the current warnings followed a detailed study examining the likely impact of prototypes, particularly on youth. The warnings address general health ("Smoking kills"), lung cancer, heart disease, addiction, low infant birthweight, and harm to others through passive smoking.

Effects of Smoking

Cigarette smoking increases the risk of coronary heart disease by itself. When it acts with other factors, it greatly increases risk. Smoking increases blood pressure, decreases exercise tolerance and increases the tendency for blood to clot. Smoking also increases the risk of recurrent coronary heart disease after bypass surgery.

The study is among the first to isolate the effects of smoking on sleep. In previous research, it was unclear whether changes in sleep patterns were due to smoking itself or to the medical conditions underlying smoking such as heart disease or respiratory disease, said study and epidemiology, in the division of pulmonary and critical care medicine, at Johns Hopkins University, in Baltimore, Maryland.

As a cigarette burns, the residues are concentrated towards the butt.

The products that are most damaging are:
• tar, a carcinogen (substance that causes cancer)
• nicotine is addictive and increases cholesterol levels in your body
• carbon monoxide reduces oxygen in the body
Cancer
• The risk of dying from lung cancer is more than 22 times higher among men who smoke cigarettes and about 12 times higher among women who smoke cigarettes compared with never smokers.
• Cigarette smoking increases the risk for many types of cancer, including cancers of the lip, oral cavity, pharynx, esophagus, pancreas, larynx (voice box), lung, uterine cervix, urinary bladder, and kidney.
The fact that smoking causes problems for the heart arteries is not surprising when you consider that smoking has been demonstrated to:
• Increase bad (LDL) cholesterol
• Lower good (HDL) cholesterol
• Increases insulin resistance
• Cigarettes are loaded with "free radicals" which "oxidize" the LDL cholesterol. Oxidized LDL is the very worst type of cholesterol.
• Directly accelerate the progression of the atherosclerotic plaque.
• Increase the heart rate and the blood pressure
Does it Cause Wrinkles
Yes. Smoking can accelerate the normal aging process of your skin, contributing to wrinkles. These skin changes may occur after only 10 years of smoking and are irreversible.
How does smoking lead to wrinkles? Smoking causes narrowing of the blood vessels in the outermost layers of your skin. This impairs blood flow to your skin, depleting it of oxygen and important nutrients, such as vitamin A. Smoking also damages collagen and elastin — fibers that give your skin its strength and elasticity. As a result, skin begins to sag and wrinkle prematurely.