How Does Alcohol Affect the Body and Brain?

Posted on January 31, 2022

man struggling with the physical effects of alcohol abuse

If you consume alcohol regularly, you risk permanent damage to your brain and body. Studies link misuse of alcohol to more than 200 diseases and injuries. Just one incident of binge drinking can result in death by alcohol poisoning or choking. Long-term alcohol use can cause irreparable brain damage or severe damage to other organs.

The 2019 National Survey on Drug Use and Health (NSDUH) estimates about 95,000 Americans died in one year from alcohol-related causes, making alcohol the third-leading preventable cause of death in the United States. The survey also found alcohol impairment accounted for 28 percent of all driving fatalities in 2019.

The good news is that once you stop using alcohol, damage to your body and brain may be reversible.

What is Alcohol Use Disorder?

Alcohol Use Disorder (AUD) is a pattern of continuing to use alcohol despite adverse consequences, difficulty controlling your drinking, needing to increase your alcohol intake to achieve the desired effect, and having withdrawal symptoms if you stop drinking.

Once known as alcoholism or alcohol abuse, AUD is a treatable, chronic disease that you can learn to manage successfully. However, because of the ways alcohol affects the brain and body, it is challenging to stop using alcohol without professional help.

If you consume large amounts of alcohol at one time or over a long period or engage in risky behavior while under the effects of alcohol, the outcome can be deadly.

How Alcohol Affects the Body

If you have ever consumed too much alcohol, you have probably woken up with a hangover. This is because alcohol causes dehydration and dilates blood vessels in the brain. Other physical symptoms of alcohol use include weakness, thirst, nausea, dizziness, light and sound sensitivity, irritability, and increased blood pressure.

Hangovers are unpleasant and give a taste of the damage alcohol can do to your body. However, binge drinking or long-term heavy drinking can have severe physical consequences, affecting most systems in your body.

Binge drinking refers to consuming large amounts of alcohol quickly and can cause alcohol poisoning. The Centers for Disease Control and Prevention (CDC) warns alcohol poisoning may shut down the part of the brain that regulates breathing, heart rate, and body temperature and can cause death.

The National Institute on Alcohol Abuse and Alcoholism warns of many chronic severe conditions associated with alcohol use, including:

  • Liver disease
  • Heart disease and stroke
  • Liver cirrhosis
  • Upper digestive tract cancers
  • Liver cancer
  • Cardiac dysrhythmia
  • Breast cancer
  • Hypertension

Some of the many systems impacted by alcohol consumption include:


While a few drinks may help you fall asleep more easily, alcohol impairs vital REM sleep, so your sleep is not restful and may be filled with nightmares or vivid dreams.


Chronic alcohol use affects electrical impulses that regulate your heartbeat and may cause cardiomyopathy, which can damage the heart’s ability to deliver blood to the body. Cardiomyopathy may result in heart failure. Heavy drinking also increases the risk of stroke and high blood pressure, which can have serious consequences, including death.

Body temperature

An overload of alcohol affects the regulation of your body temperature. If your body temperature goes too low, your body systems cannot function normally, and your heart and respiratory system can fail, causing death.

Stomach lining, intestines, and colon

Alcohol increases stomach acid, making you vomit or experience stomach pain, diarrhea, bleeding, and other gastrointestinal distress. Inflammation of the stomach lining may lead to stomach ulcers or malnutrition, as high stomach acid levels impair your ability to feel hunger.

Over time, alcohol damages the intestines and colon, causing chronic diarrhea, heartburn, and acid reflux.


The liver breaks down all substances you consume. Long-term alcohol consumption may increase fatty tissue in the liver, which restricts blood flow, damaging liver tissue. Chronic liver damage may result in liver failure or cirrhosis, a terminal illness.


Alcohol impairs the kidneys’ ability to filter the blood and regulate fluids and electrolytes. Dehydration caused by alcohol disrupts the normal function of cells, the kidneys, and other vital organs.


Alcohol inflames the pancreas and interferes with the organ’s ability to produce insulin. If the pancreas becomes unable to make insulin, you can develop diabetes. Some studies have identified a link between heavy alcohol use and pancreatic cancer.

Other ways alcohol affects the body

As mentioned earlier, alcohol can affect every system, organ, and function of the body.

Studies have found heavy or long-term use of alcohol can:

  • Suppress the immune system, so you are more likely to get sick and are at increased risk of contracting a dangerous illness like pneumonia or tuberculosis
  • Damage hormone levels and sexual function, reproductive function, menstrual cycle, and ability to get pregnant. Men may experience sexual dysfunction and decreased sperm count.
  • Affect calcium levels and hormones, increasing the risk of osteoporosis
  • Interfere with the growth of new muscle tissue
  • Contribute to hearing loss by damaging nerves in the inner ear

How Alcohol Affects the Brain

The Johns Hopkins Medicine website notes, “The brain is a complex organ that controls thought, memory, emotion, touch, motor skills, vision, breathing, temperature, hunger and every process that regulates our body.” The brain and the spinal cord make up the central nervous system (CNS).

Alcohol is a depressant, meaning it depresses the CNS, causing dysfunction in the regulatory functions of the brain, which can be life-threatening. For example, overuse of alcohol can suppress vital functions like breathing and body temperature to fatal levels.

Even moderate drinking causes cognitive and motor functions to slow down, impairing memory, judgment, and coordination. Long-term use can cause permanent brain damage.

If you stop your alcohol use, the brain may heal. But, in some cases, the damage is permanent. Research links excessive alcohol use to dementia, mental disorders, cognitive deficiencies, and learning disorders.

Studies confirm that long-term alcohol use shrinks brain cells, damaging your ability to learn, think, remember, regulate body temperature, and control your movements.

Alcohol affects the pleasure center of the brain

Addictive substances like alcohol signal the pleasure and reward center of the brain to increase levels of serotonin, dopamine, and other “happy hormones.” When these chemical messengers flood your brain, you experience a heightened sense of well-being and a powerful motivation to repeat the pleasurable experience.

While hormone levels increase naturally in response to any pleasurable experience, addictive substances cause a much more significant spike in those levels. As you continue to use alcohol, the brain adapts to its presence and starts to require increasingly greater doses to deliver the desired effect.

This need for higher doses is called tolerance and starts the cycle of dependence and addiction. If you stop using alcohol at the stage of tolerance, dependence, or addiction, you will experience withdrawal symptoms. At this point, it is challenging to stay sober without professional help.

Detoxification from alcohol can cause severe withdrawal effects and should continuously be monitored by a medical professional.

It is crucial to understand that while AUD is a chronic disease, it is highly treatable. In most cases, damage to the body and brain can be reversed or improved. It is common to struggle with both AUD and a mental health disorder simultaneously. For successful long-term recovery, simultaneous treatment of both conditions is essential. Contact your physician or an addiction specialist for recovery resources.

Rising Phoenix is a licensed mental health and substance abuse intensive outpatient program (IOP) in Scottsdale, Arizona. Our expert, compassionate team provides a full continuum of care for individuals struggling with substance use disorders, mental health, or dual diagnosis disorders.

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