People who drink alcohol regularly will acquire a tolerance to the alcohol as their liver adapts and increases the enzymes that are used to break down the alcohol. In heavy drinkers, the levels of the liver enzymes can increase threefold.
Since the liver then breaks up the alcohol faster, the drinker requires more alcohol to have the same effect.
A product of the alcohol breakdown is called ethanal, and it is a toxic chemical that interacts with molecules in the body (like protein) causing damage to liver, and can, in extreme cases lead to alcoholic liver disease.
The damage caused by over-drinking can lead to damage in a variety of organs and tissues of the body, including the brain, liver, blood vessels etc. If the drinker continues, the damage may become irreversible and extremely cause death.
Alcoholic liver disease has a number of stages associated with it.
One of the first stages is fatty liver, in which fat in the liver causes swelling because the cells become bloated with fat droplets and plasma proteins. In the early stages of fatty liver, the liver can repair itself if given the change. Stopping drinking can give the liver that time, and within a few weeks, the fatty liver is reversed. However, if the person continues to drink, the damage becomes irreversible. As cells in the liver die off or become damaged, the liver becomes fibrous and swollen. Jaundice can follow (where skin and whites of the eyes become yellow) and hepatitis. Left to continue its course of self-destruction, the liver can develop cirrhosis.
Cirrhosis of the liver occurs as more and more fibrous tissue replicates the cells in the liver, until the point comes when the liver can no longer function. Although cirrhosis is not reversible, the progress of the disease can be stopped if the patient stops drinking. However, by this time, many people are too addicted to stop, and even the threat of death is not enough.
The problem with alcohol is that it is extremely addictive, and heavy users become dependent on it. Alcohol dependence can be spotted by the following sign:
Daily consumption of alcohol, increased tolerance to the effects of alcohol, high levels of blood alcohol with little sign of being drunk, compulsive drinking.