Tolerance: Every drinker has a specific tolerance to alcohol. Below his tolerance level, the drinker can function more or less normally; at levels above his tolerance threshold, he will act intoxicated. Tolerance is therefore a condition that can only be measured accurately in a laboratory where the drinker’s blood level and behavior can be carefully monitored.
Alcoholics typically experience a dramatic climb in tolerance in the first stage of alcoholism and can often drink huge amounts of alcohol without showing obvious impairment of their ability to walk, talk, think, and react. Anyone who observes the early- and middle-stage alcoholic’s drinking behavior is familiar with the fact that the typical alcoholic can drink as much as a liter of wine, a dozen beers, or even a bottle of whisky without acting drunk.
Improved Performance: In this early, hidden stage of alcoholism, the only visible difference between the alcoholic and the non-alcoholic is improved performance in the alcoholic when he drinks and a deterioration in performance when he stops drinking.
Alcoholics in the early, adaptive stage of their disease also show improvement of functioning as the blood alcohol level begins to rise. But unlike the non-alcoholic, this improvement continues with additional drinking. Even when blood alcohol remains at fairly high levels—levels which would overwhelm the non-alcoholic, causing him to stumble, stutter, and sway—the early alcoholic is often able to talk coherently, walk a straight line, or skillfully maneuver a car. Only when the alcoholic stops drinking and his BAL descends, does his performance deteriorate—and it does so very rapidly.
Tragically, the alcoholic can only temporarily control his drinking behavior. Over a period of years, the cells’ dependence on alcohol becomes more firmly entrenched until, at some point, the alcoholic no longer has a choice. He needs alcohol to function, and he suffers terribly when he stops drinking. The benefits of adaptation are gradually overshadowed by the penalties of deterioration.
The Middle Stage of Alcoholism
As physiological changes gradually occur, the penalties of drinking begin to outweigh the benefits. Pleasurable drinking for a "high," a lift in feeling and performance from a relatively normal base, gives way to a more urgent "drinking for medicine" to "cure" the pain and misery caused by previous drinking. The basic cause of the increase in penalties is deterioration. Organs and systems that once welcomed the large doses of alcohol and tolerated its toxic aftereffects are being damaged. Now when the alcoholic stops drinking, his suffering is more severe and prolonged.
Physical Dependence: As [the alcoholic] drinks more,
and more often, to get the desired effect, the cells of
his body are soaked in alcohol for long periods of time.
The cell membranes become increasingly resistant to alcohol’s
effects, and the mitochondria within the cells increase
in size and shift functions in order to accommodate the
alcohol. With these changes, the adapted cells are able
to live and thrive in an environment where alcohol is
continually present in large amounts.
