Because they continue to work and socialize reasonably well, their deteriorating physical condition may go unrecognized by others until severe damage develops - or until they are hospitalized for other reasons and suddenly experience alcohol withdrawal symptoms. Psychological dependence on alcohol may occur with regular use of even relatively moderate daily amounts. It may also occur in people who consume alcohol only under certain conditions, such as before and during social occasions. This form of dependence refers to a craving for alcohol's psychological effects, although not necessarily in amounts that produce serious intoxication. For psychologically dependent drinkers, the lack of alcohol tends to make them anxious and, in some cases, panicky.
Physical dependence occurs in consistently heavy drinkers.
Since their bodies have adapted to the presence of alcohol, they suffer withdrawal symptoms if they suddenly stop drinking. And sometimes death. The risk of serious disease increases with the amount of alcohol consumed. Early death rates are much higher for heavy drinkers than for light drinkers or abstainers, particularly from heart and liver disease, pneumonia, some types of cancer, acute alcohol poisoning, accident, homicide, and suicide. No precise limits of safe drinking can be recommended.