Cocaine speeds up your whole body. Your heart beats fast. You talk, move, and think fast. Your body feels too hot. You might shake and twitch. You don't sleep or eat much.
Cocaine can make you feel happy and excited. But then your mood can change. You can become angry, nervous, and afraid that someone's out to get you. You might do things that make no sense.
After the high of the cocaine wears off, you can "crash" and feel tired and sad for days. You also get a strong craving to take the drug again to try to feel better.
People who snort cocaine up the nose can get nosebleeds. You can even lose your sense of smell. Your nose may be runny all the time, like you always have a cold.
People who inject cocaine will have marks where the needle went in, usually on their arms.