As you inhale cigarette smoke, nicotine moves deep into your lungs, gets absorbed into the bloodstream and quickly affects key parts of your body – not just the lungs, but also your central nervous system, your heart, and your brain. The "buzz" new smokers and regular smokers get from that first cigarette is a reaction to the release of epinephrine (also known as adrenaline), which then raises the heart rate, increases blood pressure, and constricts blood vessels. This pattern greatly increases your risk of lung cancer and can lead to heart disease, emphysema and other breathing conditions, and even a heart attack.
So why do people keep smoking cigarettes? It's the nicotine. Nicotine's addictiveness has been compared to heroin and cocaine. It creates a mental and physical dependence, and can lead to serious drug withdrawals.
But even if a person has smoked for years, it is never too late to quit! Soon after you stop smoking, your body starts to heal itself. Making the effort to quit smoking has immediate health effects and long-term lifestyle benefits.