Also, the risk of serious disease increases when heavy drinking is combined with cigarette smoking. Tolerance and Dependence are two features that characterize alcohol problems. Individuals who have developed substantial tolerance can sometimes function with few observable signs of intoxication, despite having consumed a large amount of alcohol. Psychological dependence is best characterized as a compulsive need for alcohol, especially when the person consumes alcohol in the face of obvious unfavorable consequences. Psychological dependence may be separate from physical dependence, although the two forms often occur together.
Physical dependence occurs when the body has adapted to the presence of alcohol.
Although some evidence suggests there there is a genetic basis or vulnerability for alcohol problems, little is known about what specifically might be inherited. However a major limitation of this finding is that such individuals can account for only a small percentage of those with alcohol problems. Since the majority of alcohol abusers do not have a family history of alcohol problems, environmental factors also contribute significantly to the development of alcohol problems. In summary, while some drinkers are at greater risk than others, anyone can develop alcohol problems. Present evidence suggests that alcohol abusers' drinking careers most often involve periods of drinking problems of varying severity, separated by periods of abstinence or of drinking without problems.