Nicotine is the chemical in tobacco that makes you feel good. It can also raise your blood pressure. Your heart might beat faster. You might breathe faster. And it can make you not want to eat.
People who smoke or vape might get a cough that won't go away.
People who smoke cigarettes will usually have hair, clothes, and breath that smell like cigarettes. Vaping does not leave behind the smell of tobacco, which makes it easier to hide it from parents and teachers.
People who chew tobacco tend to spit a lot.
People often sneeze when they inhale snuff.