How Alcohol Affects The Nervous System

Millions of people in the United States are currently struggling with alcohol use disorder. This is problematic because the highly addictive substance can cause a whole host of medical problems that can impact a person’s body and mind in many different ways.

Luckily, most of the damage that the condition causes can be reversed if a person receives treatment in time. If you know someone who is struggling with an alcohol use disorder, it may be helpful to understand how alcohol affects the nervous system.

How Does Alcohol Affect The Central Nervous System?

The central nervous system consists of the spinal cord and brain. It is just one part of the body’s entire nervous system. Other areas of the brain and some special organs control the rest of it.

The central nervous system’s job is to receive and process information from some parts of the body. This information allows the body to respond accordingly to the stimuli that it receives.

For example, if someone touches something hot, the central nervous system would receive the distress signal and trigger the muscles to pull back so that the skin isn’t damaged further. When a person drinks alcohol, several parts of the central nervous system are affected, which triggers a myriad of responses.

Parts of the body that the central nervous system sends and receives information through include:

• eyes
• ears
• nose
• tongue
• skin
• stomach
• muscles
• heart
• lungs
• sexual organs

How Alcohol Affects The Brain

How alcohol affects the nervous system and brain has a lot to do with its molecular size and composition. Alcohol can affect the brain quickly because it consists of tiny molecules that can easily permeate the delicate tissues of the organ.

Since alcohol is a liquid, it is absorbed faster than some of the other addictive substances that have to be broken down before they reach the bloodstream.

This causes a change in the response from the central nervous system since alcohol prevents brain receptors from being able to communicate properly.

Excitatory nerve communication is greatly affected because alcohol is a suppressant. This can lead to someone struggling to think clearly and respond accordingly to the information that they receive from their environment.

Essentially, alcohol affects the nervous system by disrupting nerve communication and slowing brain response, which in turn affects a person’s body responses.

How Alcohol Affects The Body

Alcohol affects the body by preventing the fight-or-flight response, which is controlled by the central nervous system, from being triggered. This is why a person’s breathing and heart rate become slower when they drink alcohol. It is also the reason their ability to use their senses, like sight and smell, will decline.

Men will notice that alcohol makes it more difficult for them to get or maintain erections. Women may notice that alcohol decreases their ability to become sexually excited.

Interestingly, many people falsely assume that the opposite is true because of the myth that alcohol reduces a person’s inhibitions. In reality, excessive drinking affects the central nervous system by making it more difficult to think clearly. This can lead to a person acting in ways that they normally wouldn’t consider appropriate.

Risks And Dangers Of Alcohol On The Central Nervous System

While alcohol was once thought to have some cardiovascular benefits in small amounts, current research and public health guidance have largely walked back these claims.

The World Health Organization now states that no amount of alcohol is safe from a health perspective. The effects described in this section reflect what happens in the body during alcohol consumption.

Some of the risks and dangers of conditions that can develop from alcohol’s effect on the central nervous system include:

Thiamine Deficiency

Thiamine is essential to the conversion of food into energy. Normally, a person gets all the thiamine that they need from a healthy diet. But if they regularly use alcohol, this can block the body’s ability to absorb the vitamin.

A few of the signs of thiamine deficiency are:

• development of beriberi
• loss of appetite
• fatigue
• weakness

Severe thiamine deficiency in people with alcohol use disorder can cause Wernicke-Korsakoff syndrome.

This is a serious neurological condition that combines acute confusion, eye movement problems, and coordination difficulties (Wernicke’s encephalopathy) with longer-term memory impairment and confabulation (Korsakoff syndrome).

Thiamine supplementation can treat the acute phase if caught early, but Korsakoff syndrome can cause permanent memory damage.

Alcoholic Neuropathy

Alcoholic neuropathy is caused by the damage that excessive drinking does to the peripheral nerves that are responsible for sending information between the spinal cord, brain, and other body parts.

Some of the symptoms of this condition include:

• movement disorders
• heat intolerance
• numbness and tingling
• muscle weakness
• loss of muscle tissue
• tremors
• sensation of the skin being pricked with a needle
• incontinence
• sexual dysfunction

Short-Term Nervous System Damage

If a person continues to drink alcohol to excess, they may experience many side effects to the brain, nerves, and other areas of the body.

Symptoms of short-term nervous system damage caused by alcohol use disorder include:

• balance problems
• slowed reaction time
• confusion
• decreased alertness

Long-Term Nervous System Damage

Long-term alcohol use leads to several adverse health consequences, including risks for cancer, a weakened immune system, and damage to the nervous system.

Some conditions which affect the central nervous system and can develop with prolonged alcohol abuse include:

• dementia
• permanent damage to the brain’s nerve-signal pathways
• psychosis
• depression and anxiety

Alcohol Withdrawal And The Central Nervous System

Those who drink excessively become physically dependent on alcohol.

If they try to stop drinking without medical supervision, they may experience dangerous withdrawal symptoms, which can include:

• grand mal seizures
• delirium
• psychosis
• chest pain
• hallucinations

The muscles and other organs that the central nervous system controls can be affected, too. It is common for a person who is going through alcohol withdrawal to notice that they suddenly have stronger responses to stimuli, because their body no longer has a suppressant in its system. Nightmares and mood swings are another effect of alcohol withdrawal on the central nervous system.

Anyone who drinks heavily and wants to stop should seek medical supervision rather than attempting to quit abruptly on their own. A medically supervised detox program can manage withdrawal safely with medications that reduce the risk of seizures and other serious complications.

It’s important to know that the brain retains a degree of plasticity, which is the ability to adapt and recover, even after prolonged alcohol use. Research shows that many neurological effects of alcohol use disorder can improve with sustained abstinence, proper nutrition, and thiamine supplementation. This makes receiving treatment all the more crucial.

Find Help For Long-Term Alcohol Abuse

Long-term alcohol use causes severe damage to the body and brain. Some of the damage may be treatable if a person receives the help that they need in time.

Browse our directory to find programs near you, or call SAMHSA’s free National Helpline at 1-800-662-4357.

Written by the Addiction Resource Editorial Staff