How Does Alcohol Affect the Nervous System?The National Survey on Drug Use and Health reports that over 85 percent of people of legal drinking age have consumed alcohol[i] at least occasionally. Unfortunately, social acceptance of this form of substance use can lead to significant issues when it comes to the potentially damaging impact of alcohol intake.

All people who drink undergo some baseline changes in the short-term function of their nervous systems. In addition, people who drink heavily can experience serious or severe changes in their nervous system health.

What Is the Nervous System?

The term nervous system refers to the interconnected network of nerve cells that provide the body with its most basic physical and mental functions. Some of these cells form the central nervous system[ii] (CNS), in the brain and spinal cord. The CNS serves as the headquarters for all nerve activity throughout the body. It relies on two basic components: specialized nerve cells called neurons and specialized chemicals called neurotransmitters.

Neurons and neurotransmitters have an interactive relationship. Each individual neuron forms a link in the central nervous system’s communications infrastructure. However; to send messages, these cells must call on the services of several dozen neurotransmitters. Neurotransmitting chemicals flow back and forth as required, triggering the reactions needed to carry signals to and from the central nervous system.

The central nervous system interfaces with a second network called the peripheral nervous system and includes all other nerves in the body. It carries out instructions issued by the central system and provides critical feedback to guide future CNS activity.

Alcohol’s Core Effects

Alcohol is classified as a central nervous system depressant. When consumed even in small amounts, it increases the number of neurotransmitters in the brain responsible for slowing down neuron-to-neuron communications. Under the influence of this change, brain activity decreases. In turn, messages travel more slowly and/or less frequently to parts of the body under control of the peripheral nervous system. Messages also travel more slowly or less often within the brain itself.

Many of the most notable effects of drinking are caused by alcohol’s impact on the central nervous system. They include:

  • Slurred speech
  • Visual impairment
  • Slowed muscle reactions
  • Declining body coordination
  • Memory disruptions
  • A reduced ability to think clearly or logically

The extent of the impact on normal CNS function varies according to factors such as:

  • The overall volume of alcohol consumed
  • The speed of alcohol consumption
  • The frequency of drinking episodes
  • The amount of food in a drinker’s stomach
  • The size and weight of an alcohol consumer
  • The gender of an alcohol consumer (with more significant effects in women and girls)
  • Details of a drinker’s genetic background
  • Details of a drinker’s current physical and mental health

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Alcohol and Short-Term Nervous System Damage

When consumed rapidly and in large enough amounts, alcohol can severely change the short-term function of the nervous system. Doctors and public health officials refer to this severe alteration as alcohol overdose or alcohol poisoning[iii]. Unless it’s identified and rapidly treated, alcohol poisoning can lead to life-threatening problems that include:

  • Slowed or irregular breathing
  • Complete breathing cessation
  • An irregular heartbeat
  • Complete stoppage of normal heart function
  • Uncontrolled vomiting (accompanied by major choking hazards)
  • Seizures triggered by a lack of sufficient blood sugar
  • Extreme forms of dehydration
  • An unsustainably low body temperature
  • The onset of a coma

The risks for these symptoms are especially high in people who binge on alcohol by consuming more than four or five drinks in less than two hours. Risks may also rise considerably for people who consume alcohol before reaching legal drinking age.

According to the National Institute on Alcohol Abuse and Alcoholism, “Research shows that people under age 20 typically drink about 5 drinks at one time. Drinking such a large quantity of alcohol can overwhelm the body’s ability to break down and clear alcohol from the bloodstream. This leads to rapid increases in blood alcohol content (BAC) and significantly impairs brain function.”

Alcohol and Long-Term Nervous System Damage

People who maintain a long-term pattern of heavy drinking sometimes develop a condition called alcoholic neuropathy[iv]. Neuropathy is the medical term for nerve damage. In the case of heavy drinkers, this damage occurs, in part, when the frequent presence of excessive amounts of alcohol injures nerve tissue in the peripheral nervous system. Ongoing lack of proper nutrition also plays a role. Potential symptoms of alcoholic neuropathy include:

  • Minor, moderate or severe pain in the upper or lower extremities (especially in the feet)
  • Varying degrees of extremity numbness and tingling
  • Cramping, spasming, aching or unusually weak muscles
  • Male impotence
  • An altered ability to talk or swallow
  • Bladder and urination problems
  • Abnormal changes in bowel function (leading to diarrhea or constipation)
  • An unusual inability to tolerate high temperatures

Neuropathy develops gradually. People who cut their alcohol intake, or completely stop drinking, can halt the worsening of symptoms over time. However, nothing can restore nerve function that has already been lost.

Heavy drinkers can also develop another nervous system-related ailment called Wernicke encephalopathy[v]. Triggered by a chronic vitamin B1 deficiency, this condition can lead to serious changes in normal muscle and eye function. It can also lead to a progressive decline in mental function that ultimately results in a potentially deadly coma.

Once present, Wernicke encephalopathy can set the stage for a second ailment called Korsakoff psychosis (or Korsakoff syndrome). People affected by this form of psychosis experience problems such as auditory or visual hallucinations, potentially catastrophic memory loss, an inability to create new memories and an unusual tendency to tell untrue stories. Wernicke encephalopathy and Korsakoff psychosis frequently produce their effects at the same time. For this reason, doctors tend to designate them together as Wernicke-Korsakoff syndrome.

Avoiding Serious Problems

The only reliable way to avoid severe, alcohol-related nervous system problems is to avoid drinking rapidly and in heavy amounts. Unfortunately, people affected by alcohol addiction can lose their ability to successfully control their intake. In addition, many people unaffected by clinical addiction still abuse alcohol in highly dangerous ways. Doctors refer to the sometimes-overlapping problems of addiction and abuse as alcohol use disorder[vi].

If you or your loved one are suffering from the symptoms of alcohol use disorder, the experts at Transformations Treatment Center can provide the help you need. We offer certified treatment programs including 12-step meetings, gender and age specific groups and Christian groups in a comfortable, caring environment.

  1. National Institute on Alcohol Abuse and Alcoholism: Alcohol Facts and Statistics
  2. American Association for the Advancement of Science: Alcohol and the Human Body
  3. National Institute on Alcohol Abuse and Alcoholism: Alcohol Overdose – The Dangers of Drinking Too Much
  4. U.S. National Library of Medicine – MedlinePlus: Alcohol Neuropathy
  5. U.S. National Library of Medicine – MedlinePlus: Wernicke-Korsakoff Syndrome
  6. Mayo Clinic: Alcohol Use Disorder