Alcohol and drug use affects many Canadians, and can lead to a wide range of substance use issues. Alcohol and other drugs have both short-term and long-term effects, and directly impacts individuals, families, communities, and roadways. Substance use can negatively influence your physical and mental health, damage your relationships with others, affect public safety, and lead to legal and economic issues. It is important to understand the harms of alcohol and other drug use, and know how to lower your risk of substance use related issues.