Nicotine is a primary reason for remaining a smoker, as it is an addictive agent. In general, smokers will absorb approximately about 0.2 to 2.0 mg of nicotine per cigarette. Cigarettes with low machine yields of tar have low nicotine, too. One of the main ways to reduce machine yield is to dilute the cigarette smoke with air. Yield in manufacturing means units coming out of a process divided by the number of units going into that process over a specified period. This can be done by putting air vent holes in the filter. Therefore, to get the amount of nicotine they need for their addiction, smokers tend to inhale the smoke in a more significant amount. Smokers can also easily block the air vent in the filter, which accidentally occurs by their lips and fingers, making them receive more smoke and less air. This paper will provide a short review of the effect of nicotine towards human blood.