Side Effects of Alcohol | Mental & Physical Effects of Alcohol
The side effects of alcohol fall into two groups. Short-term effects appear during a single drinking session. Long-term effects build over years of heavy drinking and damage the brain, liver, heart and mental health. Short-term effects run from impaired coordination to fatal alcohol poisoning. Long-term effects include hippocampal shrinkage, Wernicke-Korsakoff Syndrome, cirrhosis and alcohol use disorder.
Call 911 now if a person has collapsed, cannot be woken, is breathing irregularly or is having a seizure. For a mental health or suicidal crisis, call or text 988 to reach the Suicide and Crisis Lifeline, or chat at 988lifeline.org. The service is free, confidential and available 24 hours a day, with Spanish-language and ASL access.
What Does Alcohol Do to the Brain in the Short Term?
In the short term, alcohol slows the brain’s signalling within one drink, and heavy drinking in a single session impairs coordination, strips inhibition and produces alcohol poisoning, which kills when it goes untreated.
Alcohol intoxication is the first short-term effect of drinking. A single standard drink produces measurable mental effects, and those effects intensify with each additional drink. Alcohol interferes with the neurotransmitters that carry signals between brain cells, which slows how the brain processes information. Drinking heavily in one session impairs decision-making, lowers inhibition, disrupts motor coordination and produces confusion.
According to the National Highway Traffic Safety Administration, the legal limit for operating a motor vehicle is a blood alcohol concentration (BAC) of 0.08 in 49 states, the District of Columbia and Puerto Rico. Utah is the exception at 0.05, in force since December 30, 2018. NHTSA measured a 19.8% drop in Utah’s fatal crash rate in the first year under the lower limit, against 5.6% across the rest of the country. Tolerance differs between people. One person reaches the limit on a single drink; another reaches it on four or five.
There are 4 signs that a person is not fit to drive:
- Standing straight becomes impossible.
- Walking in a straight line becomes difficult.
- Bumping into people and furniture happens because they are not seen.
- Losing balance and falling becomes frequent.
Drinking beyond this point produces alcohol poisoning. The Centers for Disease Control and Prevention lists 7 symptoms of alcohol poisoning:
- Confusion about where they are
- Difficulty staying conscious
- Slow or irregular breathing
- Repeated vomiting
- Slowed heart rate
- Irregular heartbeat, meaning the heart muscle is no longer beating in rhythm
- Seizures
Untreated alcohol poisoning kills. A person showing the symptoms above needs emergency medical attention, not sleep or coffee. Call 911.
A single night of heavy drinking produces most of the short-term effects listed above. The short-term effects of alcohol are covered in full on their own page.
What Does Long-Term Drinking Do to the Brain?
Sustained heavy drinking pushes the brain’s glutamate and GABA levels out of balance, shrinks the hippocampus, and depletes the thiamine the brain needs to metabolize glucose, producing memory damage that outlasts intoxication.
Alcohol alters the levels of specific neurotransmitters. Two of the most affected are gamma-aminobutyric acid (GABA) and glutamate. The brain adjusts its own neurotransmitter levels to compensate for alcohol in the body.
Sustained heavy drinking pushes those levels further out of balance. That imbalance degrades how the brain processes information and distributes signals to the rest of the central nervous system. The long-term effects of alcohol reach every organ system.
The Hippocampus Shrinks
Topiwala and colleagues, writing in the BMJ in 2017, tracked participants for three decades and recorded the number of drinks each consumed. Participants who drank more heavily showed greater shrinkage in the hippocampus, the region that consolidates memory.
Hippocampal shrinkage degrades memory consolidation and emotional regulation.
How Does Alcohol Cause Thiamine Deficiency?
Heavy drinking also depletes thiamine, a nutrient the brain requires to metabolize glucose. Thiamine deficiency develops in people who are undernourished and in people who drink heavily over years, because alcohol blocks thiamine absorption in the gut.
Untreated thiamine deficiency produces Wernicke-Korsakoff Syndrome (WKS). The National Institute on Alcohol Abuse and Alcoholism reports that roughly 80% of people whose Wernicke encephalopathy goes untreated develop Korsakoff syndrome, the memory stage. Thiamine reverses the eye abnormalities within hours and improves the encephalopathy within 5 to 12 days. Once Korsakoff syndrome establishes, the memory damage persists, and NIAAA records that full recovery from WKS is rare even with aggressive treatment.
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Which Other Organs Does Heavy Drinking Damage?
Alcohol damages organs beyond the brain. The StatPearls review of alcohol-associated liver disease records that more than 95% of people who drink heavily develop fatty liver. Of those, 15% to 30% go on to develop cirrhosis, the extensive scarring of liver tissue. The liver takes the damage because it is the organ that metabolizes alcohol. Sustained heavy drinking overloads that capacity and destroys liver tissue faster than it regenerates.
Excessive drinking damages 5 further organ systems:
- The heart, producing cardiomyopathy and arrhythmia
- The blood vessels, producing cardiovascular disease
- The GI tract and esophagus, producing gastric ulcers
- The pancreas, producing pancreatitis
- The immune system, reducing resistance to infection
Long-term heavy drinking also raises the risk of liver cancer and breast cancer.
A person who has lost control of their drinking needs clinical assessment, not willpower. Riverside Recovery of Tampa assesses that on the phone.
What Does Alcohol Dependence Do to Mental Health?
Alcohol worsens mental health rather than relieving it. Regular drinking intensifies existing depression and anxiety, produces memory loss and difficulty learning, and raises dementia risk over years of heavy use.
People drink socially to loosen up, which is why alcohol is called a social lubricant. A person with both a substance use disorder and a mental health condition has co-occurring disorders, and regular drinking intensifies underlying depression and anxiety.
There are 4 common signs of depression:
- Sleeping far more or far less than before
- Eating far more or far less than before
- Losing interest in activities that used to bring joy
- Feeling guilt that is not the person’s fault
There are 5 common symptoms of anxiety:
- Feeling continuously restless, nervous or tense
- Breathing rapidly, a sharp rise in respiratory rate
- Racing heart rate
- Sensing impending terror or doom
- Sweating and trembling
A person who drinks regularly develops depression and anxiety. People who already have either find those symptoms intensify when they drink heavily. Regular drinking also produces memory loss and difficulty learning, and long-term heavy drinking raises dementia risk.
Sustained drinking at this level produces alcohol use disorder. Riverside Recovery of Tampa treats both conditions together through its dual diagnosis program.
What Is Alcohol Use Disorder?
Alcohol use disorder is the clinical diagnosis for addiction to alcohol. A person with AUD drinks compulsively and continues drinking in full knowledge of the damage it is doing to their health and relationships.
The most dangerous consequence of long-term alcohol use is alcohol use disorder (AUD). The National Institute on Alcohol Abuse and Alcoholism lists 9 signs of alcohol use disorder:
- Spending significant time obtaining alcohol
- Drinking in binges
- Developing financial problems from the amount spent on alcohol
- Developing cravings when going without a drink
- Continuing to drink knowing it is dangerous
- Damaging relationships with family, friends and colleagues
- Needing greater amounts to achieve the same effect, because of tolerance
- Lying about how much they drink and hiding the amount
- Dropping activities that used to matter to keep drinking
Alcohol use disorder damages health in proportion to how much a person drinks and for how long. The body adapts to constant alcohol in the bloodstream, and its sudden absence throws that adaptation into crisis. That crisis is alcohol withdrawal syndrome.
What Happens During Alcohol Withdrawal?
Stopping suddenly after long-term drinking produces alcohol withdrawal syndrome. Seizures occur in roughly 3% of cases and delirium tremens in 3% to 5%, and untreated delirium tremens kills up to 35% of the people who develop it.
The brain’s neurotransmitters have rebalanced around constant alcohol. Removing it forces an abrupt correction, and withdrawal symptoms are that correction. Withdrawal follows other addictions too, but alcohol withdrawal is one of the few that kills.
There are 9 mild alcohol withdrawal symptoms:
- Fevers
- Sweats
- Nausea and vomiting
- Abdominal cramps and pain
- Irritability, agitation and emotional lability
- Shakes and tremors
- Headaches
- Difficulty sleeping despite exhaustion
- Nightmares and insomnia
As the syndrome progresses, severe symptoms replace these. There are 7 severe alcohol withdrawal symptoms:
- High, spiking fevers
- Shakes and tremors severe enough to prevent holding anything
- Rapid heart rate
- Blood pressure high enough to be dangerous
- Intractable vomiting
- Severe dehydration
- Uncontrollable seizures
Seizures are what make alcohol withdrawal life-threatening. The StatPearls review of delirium tremens records that seizures occur in roughly 3% of alcohol withdrawal cases, and seizures that are not stopped produce brain damage. Withdrawal seizures also form part of delirium tremens.
Delirium tremens, shortened to DTs, occurs in 3% to 5% of people in alcohol withdrawal, and the risk rises with the volume and duration of drinking. DTs produces visual and auditory hallucinations, severe confusion and disorientation alongside the symptoms above. DTs is a medical emergency. Call 911. StatPearls puts untreated mortality at up to 35%, falling to between 1% and 4% with hospital treatment. That difference is the entire argument for medically supervised detox.
Not everyone with alcohol use disorder develops every symptom above. Underlying physical health, the volume consumed and the duration of drinking determine which symptoms appear and how severe they become. StatPearls records that withdrawal begins 6 to 24 hours after the last drink, and that DTs, where it develops, starts as early as 48 hours and lasts up to 5 days.
Why Does Alcohol Withdrawal Need Medical Supervision?
Alcohol use disorder requires medical treatment. Clinicians manage withdrawal, protect against seizures and delirium tremens, and treat the physical and mental damage already done.
Medical supervision covers detox, the withdrawal period itself and the management of cravings afterwards. Riverside Recovery of Tampa provides that care, and the alcohol withdrawal page sets out what the process involves.
Where Can You Get Alcohol Use Disorder Treatment in Tampa?
Riverside Recovery of Tampa treats alcohol use disorder in Tampa, Florida, with a clinical team of 16 working alongside 5 medical providers, accredited by CARF and The Joint Commission.
Riverside Recovery of Tampa builds each treatment plan around the individual, and insurance is verified during a phone assessment before arrival.
Centers for Disease Control and Prevention. Alcohol Poisoning Deaths. cdc.gov
Topiwala A, Allan CL, Valkanova V, et al. Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study. BMJ. 2017;357:j2353. National Library of Medicine
National Institute on Alcohol Abuse and Alcoholism. Wernicke-Korsakoff Syndrome. Source for the 80% progression to Korsakoff syndrome without treatment and the thiamine response times. niaaa.nih.gov
National Institute on Alcohol Abuse and Alcoholism. What are the symptoms of alcohol use disorder (AUD)? rethinkingdrinking.niaaa.nih.gov
Rahman A, Paul M. Delirium Tremens. StatPearls. Source for withdrawal seizure and DTs prevalence, untreated and treated mortality, and onset timing. National Library of Medicine
National Highway Traffic Safety Administration. Utah’s .05 Law Shows Promise to Save Lives, Improve Road Safety. Source for the 0.05 limit in Utah and the first-year crash-rate comparison. nhtsa.gov
Alcohol-Associated Liver Disease. StatPearls. Source for the proportion of people who drink heavily developing fatty liver and cirrhosis. National Library of Medicine
