Drugs can affect feelings and moods, judgment, decision making, learning, and memory. But they can also cause or worsen other health problems—cancer; heart disease; lung disease; liver function; mental disorders; and infectious diseases such as HIV/AIDS, hepatitis, and tuberculosis.
Explanation:
Drugs excite the parts of the brain that make you feel good. But after you take a drug for a while, the feel-good parts of your brain get used to it. Then you need to take more of the drug to get the same good feeling. Soon, your brain and body must have the drug to just feel normal.