Individual - The use of illegal drugs affects the body by changing one’s appetite, wakefulness, blood pressure and mood. These drugs may cause heart attack, stroke, psychosis, and illnesses such as cancer, HIV/AIDS, and hepatitis. Drugs also affect the brain which causes changes in how the individual experiences normal pleasures in life such as food, changes in one’s ability to control the stress level, and changes in decision-making and learning/remembering abilities (NIDA, 2017).