From nose to toe, alcohol goes wherever water can be found in the body. It quickly crosses the intestine and enters the bloodstream, diffusing in and out of cells at random. But it doesn't enter fat, which helps explain why men can "hold their liquor" better than women. Men have a higher muscle-to-fat ratio. Since muscle contains a lot of water, men contain more water. The extra water dilutes the alcohol more in men, comparatively lowering their blood alcohol levels when men and women consume the same number of drinks. Nearly every part of the body can be affected by alcohol, depending on the amount.


From learning and memory to balance and reflexes, alcohol affects the entire central nervous system. It appears to change the actions of neurotransmitters -- the chemicals that carry signals between nerve cells -- by changing the outer membranes of the nerve cells. One experimental drug, RO-154513, can reverse the effects of alcohol by stabilizing the action of one of the neurotransmitter systems. With long-term use of alcohol, brain damage becomes permanent.


Alcohol has been shown to raise blood pressure and cause heart muscle deterioration.


Constantly bathing the stomach walls with alcohol causes the secretion of acids that can lead to peptic ulcers and bleeding. Stomach cancer also has been linked to alcohol abuse.


With chronic consumption, portions of the liver speed up the processing of alcohol, diverting blood to those regions while depriving others. Liver cells in the deprived areas suffocate and eventually die. The process of filling in these regions with scar tissue leads to cirrhosis.


The production of both red and white blood cells can be inhibited by chronic alcohol abuse. Without sufficient red cells to carry oxygen, the body becomes anemic. Without sufficient white cells, the immune system fails to function properly and the individual becomes more easily infected by bacteria and viruses.


Extended alcohol use can reduce the production of male sex hormones, lowering both the sex drive and sexual performance. It also can alter female hormones, including altering the menstrual cycle. Alcohol abuse during pregnancy can lead to birth defects.