what does tobacco do
1 Nicotine, the drug that makes tobacco addictive, goes to your brain very quickly. 2  Nicotine makes you feel good when you are smoking, but it can make you anxious, nervous, moody, and depressed after you smoke.3  Using tobacco can cause headaches and dizziness.eart. 1  Smoking increases your heart rate and blood pressure and causes heart disease and heart attacks. 2  If you try to do activities like exercise or play sports, your heart has to work harder to keep up.