Substance abuse describes a pattern of substance (drug) use leading to significant problems or distress such as failure to attend school, substance use in dangerous situations (driving a car), substance-related legal problems, or continued substance use that interferes with friendships and/or family relationships. Substance abuse, as a disorder, refers to the abuse of illegal substances or the abusive use of legal substances. Alcohol is the most common legal drug of abuse. People can often stop substance abuse on their own or with a little help when they realize it is interfering with their life. Alcohol is the substance most often used by adolescents. About 70% of 12th graders report having tried alcohol, although only 55% say they have ever been drunk. About 50% of 12th graders have consumed alcohol in the past month and are considered current drinkers. Heavy alcohol use is also common, and nearly 90% of all alcohol consumed by adolescents occurs during a binge. A binge is generally considered to be consuming more than 4 drinks within 2 hours or less. However, for small people, such as younger girls, as few as 2 drinks may cause enough intoxication to be considered a binge.