Drugs can be legal like alcohol, tobacco, and caffeine or illegal like cocaine, meth, cannabis, and heroin. Cocaine is a recreational drug that can be snorted, inhaled, or injected and causes physical symptoms such as loss of contact with reality, a fast heart rate, and enlarged pupils due to its addictive effect on the brain's reward pathway. Tobacco is the main component in cigarettes and dip and gives smokers a greater risk of lung cancer and heart failure despite more than 70 species of tobacco plants existing.