Like it or not, alcohol is a poison. Even the doctor or nurse rubs alcohol on the body prior to an injection in order to kill any pathogenic micro-organisms which might be lingering on the skin. Its killing capacity is that effective and dependable. Why then do not people understand that the over-consumption of alcohol can have highly destructive effects on their organs and tissues?
Just one sip of beer, wine, or whisky hangs out in your body for about 2 hours. Once it quickly enters your bloodstream, it touches down on nearly every organ and system in your body. 
The real question here concerns how alcohol will affect your vital organs, especially your heart and brain. Since the brain has always been said to actually lose many a brain cell with each glass of alcoholic beverage, what’s the real story?
Contrary to popular belief, alcohol doesn’t actually kill your brain cells, says David Sack, M.D., CEO of addiction-treatment company Elements Behavioral Health.
But alcohol does alter levels of neurotransmitters, the chemical messengers that control your mood, perception, and behavior, he says.
Alcohol impairs brain areas such as the cerebellum—the control site for your balance and coordination—and your cerebral cortex, which is responsible for thinking, memory, and learning, says Kimberly S. Walitzer, Ph.D., deputy director of the University at Buffalo’s Research Institute on Addictions.
Plus, University of Michigan researchers found the amygdala—an area of the brain involved in fear and anger—showed less of a reaction to threatening faces after a single drink, potentially explaining why you’re prone to risky behavior (like fighting a bouncer) under the influence. 
The heart muscle is quite susceptible to the various harmful effects of alcohol. Because heart rate and heartbeat are both vital signs that should not deviate too much from a person’s normal readings, the actual effects of alcohol consumption ought to be monitored closely.
Two drinks per day can raise your risk of atrial fibrillation by 17 percent, according to a study in the Journal of the American College of Cardiology.
This type of irregular heartbeat approximately quadruples your risk of having a stroke and triples your risk of heart failure. 
Next up is the stomach and liver. Because they receive the brunt of processing the alcohol, the stomach and liver suffer the most initially. The detoxification pathways of the liver, in particular, will become compromised the longer and the greater the volume that is consumed. When alcohol toxicity in the liver exceeds a certain threshold, the greater the likelihood that Cirrhosis will develop. A sustained level of alcohol in the body will also significantly exacerbate cases of Hepatitis C.
As for the stomach:
Just one night of binging—that’s five drinks or more for guys in about 2 hours—increases what’s called your gut permeability, according to University of Massachusetts Medical School researchers.
Harmful toxins and bacteria leak from your digestive system into your bloodstream, prompting a dangerous immune-system response that can eventually lead to liver disease and other health problems.
At lower doses, alcohol irritates your stomach, increases acidity, and relaxes the muscle at the end of your esophagus, causing heartburn, Dr. Sacks says. 
The following diagram presents a concise list of excellent reasons not to drink alcohol. As some of the more famous healers of the last century pointed out: alcohol is best used as a sterilizing agent in medicine, not a drinking beverage at a social gathering.
Everyone knows that women should never drink during their pregnancy because of the profound damage that is caused to the developing fetus. It’s a scientific fact that “alcohol (wine, beer, or liquor) is the leading known preventable cause of developmental and physical birth defects in the United States.” 
Therefore, it ought to be obvious that the mother is also harmed, as is anyone who imbibes alcohol on a regular basis. Particularly those who possess the gene for alcoholism are susceptible to alcohol poisoning, which is responsible for countless premature deaths worldwide. They are likewise vulnerable to many of the anti-social behaviors which can lead to job loss, divorce and imprisonment due to excessive DUIs.
 Yahoo Health