Accordinggetting treatment to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), close to three-quarters of the adult population in the United States (aged 18 and older) consumed alcohol in the year leading up to the 2014 national survey, and over half reported past-month drinking. Alcohol consumption if over the legal age of 21 isn’t necessarily detrimental to one’s health if it is being used responsibly and within limits.

The Dietary Guidelines for Americans publishes that excessive drinking, which is more than four drinks a day or eight in a week for a woman, or more than five drinks a day or 15 in a week for a man, is where the problem lies. Any drinking under the age of 21, or by a pregnant women, is considered harmful as well. A “drink” is defined by the Dietary Guidelines as follows:

  • One beer or malt beverage (12 ounces) at 5 percent alcohol
  • One glass of wine (5 ounces) at 12 percent alcohol
  • One shot of spirits (1.5 ounces) at 40 percent alcohol
  • One alcoholic drink contains 14 grams of alcohol (0.6 fl ounces of pure alcohol)

The alcohol people drink usually comes via a fermentation process and is called ethyl alcohol. People swallow it, and it travels from the mouth to the small intestines and then into the bloodstream where it enters into the brain. There, it alters the brain’s chemistry and disrupts some of its chemical messengers.

Alcohol is a mind-altering substance that takes effect rapidly, within several minutes of consumption. It is filtered out of the body by the liver. Alcohol acts as a depressant to the central nervous system, slowing down heart rate and blood pressure and lowering body temperature. In small amounts, alcohol can lower inhibitions, increase sociability, and promote good feelings. In larger amounts, alcohol can impair a person’s reaction time and motor coordination as well as cognitive abilities and memory functions. Slurred speech, falling down, and questionable choices are all potential signs of alcohol intoxication.

When someone drinks, they raise their blood alcohol concentration levels, or BAC. In general, anything above 0.08 g/dL is considered intoxicated, as this is the legal limit in all 50 states for driving purposes, the DMV publishes.

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      How much it takes for one person to get drunk and how individuals metabolize alcohol differ from person to person. Women tend to metabolize alcohol more slowly than men do, meaning that it typically takes less alcohol for a woman to become intoxicated than a man. Genetics can also play a role as well. Around half of those from regions of East Asia, such as Northeast China, Korea, and Japan, may experience the “Asian flush” or “glow” when they drink alcohol, Yale Scientific reports. This means that they lack a particular enzyme, due to a genetic variant, that allows the liver to break down alcohol safely, leading to rapid intoxication and other complications, which in turn makes them less likely to want to abuse alcohol.

      The amount of food a person eats before drinking can also affect levels of intoxication as can the pace at which alcohol is consumed. The more alcohol that is consumed in a short period of time, the harder it is for the liver to break it down and the more intoxicated a person becomes. Age, weight, medical conditions, and the introduction of other substances, such as medications or illicit drugs, can also impact alcohol metabolism.

      Drinking alcohol regularly creates tolerance, meaning that it will take more alcohol to get drunk. Individuals with higher tolerance levels may not become intoxicated with lower amounts anymore. As a general rule, NIAAA publishes that drinking alcohol in moderate amounts constitutes low-risk drinking, and any patterns that go beyond these amounts can create a range of possible issues.

Alcohol Poisoning and Alcohol-Related Deaths

When alcohol is not able to be metabolized fast enough by the body, a toxic buildup of chemicals can occur, leading to an overdose (often called alcohol poisoning). One of the most common forms of excessive drinking in America is binge drinking, which occurs when an individual raises their BAC to above 0.08 g/dL, often by drinking four or more drinks in a span of two hours or less. The Centers for Disease Control and Prevention (CDC) publishes that over 50 percent of all of the alcohol consumed within the United States is done via binge drinking.

Binge drinking has many negative effects, not the least of which is the potential for alcohol poisoning. The World Health Organization (WHO) reports that 3.3 million people around the globe die annually from harmful use of alcohol. Every year 2,200 people in the United States die from alcohol poisoning, which the CDC publishes equated to six alcohol poisoning fatalities every day between the years 2010 and 2012.

Alcohol poisoning symptoms include:

      • Slow or irregular breathing
      • Weak pulse
      • Bluish color to the nail beds, lips, and/or skin
      • Low body temperature and being cold to the touch
      • Tremors or seizures
      • Vomiting
      • Severe confusion
      • Significant drowsiness or loss of consciousness

Alcohol poisoning requires immediate medical attention and can be reversed with swift action.

Impaired driving and alcohol-related car crashes another risks of excessive drinking. Someone is killed in a car crash involving a driver under the influence of alcohol more than once every hour of every day in the United States, the CDC reports, and 28 people die every day in a motor vehicle accident due to an alcohol-impaired driver. Alcohol slows reaction time, the capability to sense danger, perceptions, concentration levels, and the ability to process information, making alcohol consumption and driving a dangerous combination.

Alcohol is the fourth-leading cause of deaths that are considered preventable in America. NIAAA publishes that 88,000 people die every year from an alcohol-related factor.

Damage to the Cardiovascular System

Many studies have touted the benefits of moderate alcohol consumption, which include a lower incidence of coronary artery or blood vessel disease and a lowered mortality rate of dying from a heart attack, Harvard Health publishes. Excessive drinking, however, can raise the level of triglycerides in the bloodstream and thereby damage the cardiovascular system, potentially leading to stroke, heart failure, obesity, or an increased incidence of developing diabetes due to taking in a lot of empty calories in the form of alcoholic drinks, the American Heart Association warns.

Regular bouts of heavy drinking can cause heart disease or sudden cardiac death. Alcohol can be toxic to the heart, causing arrhythmias (an irregular heart rate), alcoholic cardiomyopathy (weakening and stretching of the heart muscle and thinning of the left ventricle wall caused by the inability of the heart to pump blood as effectively), congestive heart failure, or sudden cardiac death. Chest pain, shortness of breath, tingling or numbness in extremities, swelling of the feet and/or legs, and fatigue are common symptoms of heart disease, heart failure, or damage to the heart.

Alcohol abuse has long been linked to liver disease, which can be fatal. More than 18,000 people died from alcohol-related liver disease in 2013 in the United States, the CDC reports. Alcohol-related liver disease (ARLD) generally occurs in three stages: alcoholic fatty liver disease, alcoholic hepatitis, and cirrhosis. The liver helps to filter out toxins, and alcohol is no exception. With continued alcohol abuse, however, fat begins to build up and get deposited into the cells of the liver. An individual may feel fatigued, have pain in their upper right abdomen, and feel weak, although many times those suffering from alcoholic fatty liver disease will have no symptoms. This is the earliest stage of ARLD, and it is potentially reversible with abstinence from alcohol.

Alcoholic hepatitis is the second stage of ARLD. In addition to accumulating fat deposits, the liver may also become inflamed and scar tissue may begin to build up. This stage of ARLD can be relatively mild or more severe, and it can even lead to liver failure and death. Loss of appetite, nausea, vomiting, fatigue, fever, jaundice (a yellow tinge to the skin and whites of the eyes), and abdominal pain are common side effects of alcoholic hepatitis. In mild form, alcoholic hepatitis can be reversed with sobriety.

The American Liver Foundation warns that 35 percent of heavy drinkers may suffer from alcoholic hepatitis and 10-20 percent may develop cirrhosis, the most advanced form of ARLD. Cirrhosis of the liver occurs when scar tissue replaces the normal tissue of the liver and interferes with its ability to function, which can lead to liver failure and death. In addition to the symptoms of alcoholic hepatitis, those suffering from cirrhosis may experience a buildup of fluid in the abdomen, have a decreased ability to filter toxins, and exhibit decreased mental capabilities. Cirrhosis caused by alcohol is not reversible, although symptoms can be managed and progression of the disease halted if alcohol use is stopped.

Alcohol causes about 3.5 percent of all cancer deaths in the United States, according to studies published in the American Journal of Public Health (AJPH). The National Cancer Institute explains that the more alcohol a person

  • Breast cancer
  • Esophageal cancer
  • Liver cancer
  • Cancers of the neck and head (larynx, pharynx, and oral cavity cancers)
  • Colorectal cancer

Alcoholic beverages may contain chemicals that act as carcinogens, and alcohol itself is metabolized into acetaldehyde, which is probably also carcinogenic. Alcohol also impedes the normal functions of the immune system and prevents certain nutrients and vitamins from being metabolized naturally, increasing the risk factors for many types of diseases and health problems. It can also interfere with regular functions of the white blood cells in the body that generally work to help fight off disease and infection. Individuals who drink alcohol regularly may have more unsafe sexual encounters, due to lowered inhibitions and impaired decision-making abilities, that can lead to the contraction of an infectious or sexually transmitted disease (STD). WHO states that excessive alcohol consumption is a risk factor for more than 200 injury and disease situations.

Alcohol interferes with normal production and transmission of some of the chemical messengers in the brain, including dopamine, which is related mood regulation and feelings of happiness. With repeated use of alcohol, the brain becomes accustomed to alcohol’s disruption of dopamine levels, and it begins to produce less of the neurotransmitter on its own. When dopamine levels drop without the presence of alcohol, depression, anxiety, and difficulties feeling pleasure result. Cravings for alcohol and uncomfortable withdrawal symptoms may crop up when alcohol wears off, causing individuals to drink more. In so doing, they may lose control over their consumption levels and become addicted to alcohol. NIAAA estimates that more than 16 million adults in the United States (18 and older) suffered from an alcohol use disorder (AUD) in 2014.

One of the side effects of addiction involving alcohol is alcohol dependence. When someone who is dependent on alcohol stops drinking suddenly, severe withdrawal symptoms may occur that can even be fatal without professional help. In addition to disrupting levels of dopamine in the brain, alcohol serves as a central nervous system (CNS) depressant, which means that it stimulates the release of GABA (gamma-aminobutyric acid), which acts as a sedative. Blood pressure, body temperature, respiration, and heart rate are all decreased in the presence of high levels of GABA. If GABA levels suddenly drop, after being interfered with by chronic alcohol abuse, the CNS may rebound, causing the autonomic functions that were previously suppressed to spike. This can produce extremely negative side effects and even become fatal.

The most significant form of alcohol withdrawal, that affects 3-5 percent of individuals battling alcohol withdrawal, is delirium tremens, or DTs, the New England Journal of Medicine (NEJM) publishes. With DTs, fever, hallucinations, confusion, and seizures that can be life-threatening occur. Other side effects of alcohol withdrawal include tremors, nausea, vomiting, headache, stomach pain, muscle weakness, fatigue, insomnia, rapid heart rate, hypertension, sweating, shallow breathing, short-term memory loss, and difficulties concentrating.

Early and Long-Term Effects of Alcohol Abuse

Drinking alcohol at an age before the brain is done developing, say in early adulthood or adolescence, may increase the odds for developing a substance use disorder down the line. The National Survey on Drug Use and Health (NSDUH) of 2013 reports that individuals who drank alcohol before age 14 were over five times more likely to suffer from alcohol dependence or abuse issues than those who waited until they were 18 to take their first drink.

      • Alcohol damages the cerebral cortex, cerebellum, and hippocampus in the brain, the National Institute on Drug Abuse (NIDA) publishes. The cerebellum manages coordination and movement while the cerebral cortex is involved in decision-making and problem-solving skills. The hippocampus deals with learning and memory functions. NIAAA warns that alcohol may shrink the brain’s mass and impede the functions of the neurotransmitter glutamate, which affects memory and may be why some people suffer from “blackouts” when the drink too much. A blackout is a period of time that the individuals is unable to remember after drinking large amounts of alcohol.
      • Another potential side effect of chronic and excessive drinking on the brain is the potential for developing alcohol-related dementia in the form of Wernicke-Korsakoff syndrome (WKS). WKS is actually two different diseases. Wernicke’s encephalopathy is the first stage and is the result of the severe depletion of thiamine, or vitamin B1, which is caused by regular and excessive alcohol consumption over a period of years. Symptoms include mental confusion, ataxia (lack of muscle coordination), nystagmus (involuntary eye movements), and double vision. Without proper and swift treatment, Wernicke encephalopathy can lead to coma and even death, and 85 percent of the time will develop into Korsakoff syndrome, the Oxford Journal publishes.

Korsakoff syndrome is nonreversible and indicated by severe mental impairments, including the inability to form new memories, hallucinations, and confabulation (making up of stories).


Korsakoff syndrome is a severe form of dementia, caused by alcohol abuse, that can render people unable to take care of themselves. It can be fatal without professional treatment.

While alcohol abuse can cause various physical effects and health issues, some of the alterations in the brain caused by alcohol may be reversible over time with complete abstinence. Drinking large amounts of alcohol regularly, or consuming any alcohol at a young age, can create a wide range of physical health problems and damage to internal organs, including the brain.