How does nicotine affect your body?
Nicotine is only one of the thousands of chemicals in tobacco, but it is the major component that acts on the brain.
When you inhale, your lungs readily absorb nicotine from the smoke of cigarettes, cigars, or pipes. The tissues of the mouth also absorb nicotine when you chew tobacco or smoke a cigar or pipe, even if you don't inhale. The nicotine reaches your brain in seconds. It has a direct effect on your body for up to 30 minutes.
In the body, nicotine both stimulates and slows down your central nervous system. You feel the stimulant effect and pleasurable sensation right away. It makes you more alert, relaxes your muscles, improves your memory and attention, and makes you less irritable. It causes a sudden increase in blood pressure, breathing rate, and heart rate. This stimulation is followed by depression and fatigue, causing you to want another cigarette.
When you use tobacco regularly, the levels of nicotine build up in your body during the day and last through the night. This exposes you to the effects of nicotine for 24 hours.
Nicotine is very addictive. The more you use nicotine, the more nicotine you need to feel the same effect. This is called tolerance. And repeated use causes withdrawal when you try to quit.