Definitions
Risky drinking (also called hazardous drinking) is defined by drinking above the recommended limits:

greater than 14 standard drinks units per week or greater than 4 standard drinks on a single occasion in men
greater than 7 standard drinks units per week or greater than 3 standard drinks on a single occasion in women
any drinking in pregnant women or persons < 21 years oldBinge drinking is a pattern of alcohol consumption that brings blood alcohol concentration ≥ 0.08%, usually corresponding to

≥ 5 standard drinks on a single occasion in men
≥ 4 standard drinks on a single occasion in womenIn the DSM-IV, alcohol abuse and alcohol dependence were defined as distinct disorders from 1994 to 2013. The DSM-5 combined those two disorders into alcohol use disorder with sub-classifications of severity. The DSM-IV definition is no longer used. There is no "alcoholism" diagnosis in medical care. Alcohol misuse is a term used by United States Preventive Services Task Force to describe a spectrum of drinking behaviors that encompass risky drinking, alcohol abuse, and alcohol dependence (similar meaning to alcohol use disorder but not a term used in DSM). Signs and symptoms
Individuals with an alcohol use disorder will often complain of difficulty with interpersonal relationships, problems at work or school, and legal problems. Additionally, people may complain of irritability and insomnia. Alcohol abuse is also an important cause of chronic fatigue. Signs of alcohol abuse are related to alcohols effects on organ systems. However, while these findings are often present, they are not necessary to make a diagnosis of alcohol abuse.
If alcohol-induced neurotoxicity has occurred a period of abstinence for on average a year is required for the cognitive deficits of alcohol abuse to reverse.College/university students who are heavy binge drinkers (three or more times in the past two weeks) are 19 times more likely to be diagnosed with alcohol dependence, and 13 times more likely to be diagnosed with alcohol abuse compared to non-heavy episodic drinkers, though the direction of causality remains unclear. Occasional binge drinkers (one or two times in the past two weeks), were found to be four times more likely to be diagnosed with alcohol abuse or dependence compared to non-heavy episodic drinkers. Epidemiology
Alcohol abuse is said to be most common in people aged between 15 and 24 years, according to Moreira 2009. However, this particular study of 7275 college students in England collected no comparative data from other age groups or countries. Causes of alcohol abuse are complex and are likely the combination of many factors, from coping with stress to childhood development. The US Department of Health & Human Services identifies several factors influencing adolescent alcohol use, such as risk-taking, expectancies, sensitivity and tolerance, personality and psychiatric comorbidity, hereditary factors, and environmental aspects.Studies show that child maltreatment such as neglect, physical, and/or sexual abuse, as well as having parents with alcohol abuse problems, increases the likelihood of that child developing alcohol use disorders later in life.