What It Is: Nicotine is a highly addictive stimulant found in tobacco that is quickly absorbed into the bloodstream when smoked. How It's Used: Nicotine is typically smoked in cigarettes or cigars. Some people put a pinch of tobacco (called chewing or smokeless tobacco) into their mouths and absorb nicotine through the lining of their mouths. Some people inhale nicotine through the nose. What It Does: Nicotine is as addictive as heroin or cocaine, which makes it extremely difficult to quit. Those who start smoking before the age of 21 have the hardest time breaking the habit. Physical effects of nicotine use include rapid heartbeat, increased blood pressure, shortness of breath, and a greater likelihood of colds and flu. Users have an increased risk for lung diseases like lung cancer, heart disease, and stroke. They may have bad breath and yellowed teeth, and are more likely to get cancers of the mouth and neck. Withdrawal symptoms of nicotine include anxiety, anger, restlessness, and insomnia. Back to Articles Related Articles Vaping: What You Need to Know E-cigarettes aren't a safe alternative to smoking, they're just another way of putting nicotine into your body. Get the facts on e-cigs and vaping. Read More Vaping: What You Need to Know E-cigarettes are marketed as a safe alternative to smoking, but they're not. They still deliver nicotine into the body and damage the lungs. Here are the facts on vaping. Read More Smokeless Tobacco Chewing or dipping: These terms are familiar to the millions of teens who use smokeless tobacco. If you're ready to quit or you want to learn more about smokeless tobacco, read this article. Read More Word! Nicotine This chemical is found in cigarettes and is the reason why kids (and others) get hooked on the smoking habit. Read More Secondhand Smoke Breathing in someone else's secondhand smoke is hazardous to our health. Find out what you can do about it. Read More Smoking and Asthma Find out why smoking is a bad idea - especially for people with asthma. Read More How Can I Help My Teen Quit Smoking for Good? Find out what the experts say. Read More Helping a Parent Who Smokes You love your mom and dad, but what if they smoke? Find out how you can help them be healthier. Read More Kids and Smoking The health risks of smoking are well known, many young people still do it. Here's how to help your kids avoid smoking, vaping, or using chewing tobacco - or quit, if they've already started. Read More Smoking and Asthma Being a smoker is an obvious risk for kids and teens with asthma, but just being around people who smoke - and breathing in secondhand smoke - can cause problems, too. Read More Smoking Stinks! Everyone says smoking is bad for you. Why? Find out in this article for kids. Read More Smoking and Asthma Smoking - or even breathing in secondhand smoke - can make asthma worse. Find out more in this article for kids. Read More Smoking Smoking is on the decline, but some people are still lighting up. Why? The answer is addiction. Find out more in this article for teens. Read More Secondhand Smoke Experts now know that breathing in someone else's secondhand smoke is bad for you. Find out what you can do about it. Read More How Can I Quit Smoking? Nearly 1 in 5 deaths in the United States is related to tobacco. Are you ready to kick the habit? Read More Dealing With Peer Pressure Did you ever feel like another kid was trying to get you to do something you didn't want to do? If so, you've felt peer pressure. Find out more in this article for kids. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.