Alcohol Use

Alcohol has almost immediate effects because it is absorbed faster than it is processed (metabolized) and eliminated from the body. As a result, alcohol levels in the blood rise rapidly. Effects can occur within a few minutes of drinking.

Effects vary greatly from person to person. For example, people who drink regularly (2 or more drinks per day) are less affected by a given amount of alcohol than those who normally do not drink or drink only socially, a phenomenon termed tolerance. People who have developed tolerance to alcohol may also be tolerant to other drugs that slow brain function, such as barbiturates and benzodiazepines.

Effects vary depending on the level of alcohol in the bloodstream, which is usually expressed in the United States in terms of milligrams per deciliter (1/10 liter of blood), abbreviated mg/dL and in other parts of the world as millimoles per liter abbreviated mmol/L. Actual blood levels required to produce given symptoms vary greatly with tolerance, but in typical users who have not developed tolerance, the following symptoms are typical:

Vomiting is common with moderate to severe alcohol intoxication. Because people may be very drowsy, vomited material may enter the lungs (be aspirated), sometimes leading to pneumonia Aspiration Pneumonia and Chemical Pneumonitis Aspiration pneumonia is lung infection caused by inhaling mouth secretions, stomach contents, or both. Chemical pneumonitis is lung irritation caused by inhalation of substances irritating or... read more and death.

In the United States, all states define driving with a blood alcohol content (BAC) at or above 80 mg/dL (17.4 mmol/L; 0.08%) as a crime, but specific state laws and penalties vary.

In people who do not drink regularly, a blood alcohol level of 300 to 400 mg/dL (65.1 to 86.8 mmol/L) often causes unconsciousness, and a blood alcohol level of ≥ 400 mg/dL (≥ 86.8 mmol/L) can be fatal. Death can occur due to impaired breathing or abnormal heart rhythms (arrhythmia Overview of Abnormal Heart Rhythms Abnormal heart rhythms (arrhythmias) are sequences of heartbeats that are irregular, too fast, too slow, or conducted via an abnormal electrical pathway through the heart. Heart disorders are... read more ), especially when large quantities are drunk rapidly. Low blood pressure Low Blood Pressure Low blood pressure is blood pressure low enough to cause symptoms such as dizziness and fainting. Very low blood pressure can cause damage to organs, a process called shock. Various drugs and... read more and low blood sugar levels Hypoglycemia Hypoglycemia is abnormally low levels of sugar (glucose) in the blood. Hypoglycemia is most often caused by medications taken to control diabetes. Much less common causes of hypoglycemia include... read more can be caused by drinking large amounts of alcohol.

The effects of a particular blood level differ in chronic drinkers. Many seem unaffected and appear to function normally with relatively high levels, such as 300 to 400 mg/dL (65.1 to 86.8 mmol/L).

Alcohol, even in moderate doses, interferes with short-term memory formation which may cause blackouts. The intoxicated individual may seem gregarious and loquacious but will have limited memory of the blackout period.

Prolonged use of excessive amounts of alcohol damages many organs of the body, particularly the liver (alcohol-related liver disease Alcohol-Related Liver Disease ). Because people may not eat an adequate diet, they may also develop severe vitamin and other nutritional deficiencies.

Alcohol-related liver disease Alcohol-Related Liver Disease Alcohol-related liver disease is liver damage caused by drinking too much alcohol for a long time. In general, the amount of alcohol consumed (how much, how often, and for how long) determines... read more includes liver inflammation (hepatitis Overview of Hepatitis Hepatitis is inflammation of the liver. (See also Overview of Acute Viral Hepatitis and Overview of Chronic Hepatitis.) Hepatitis is common throughout the world. Hepatitis can be Acute (short-lived) read more ), fatty liver Fatty Liver Fatty liver is an abnormal accumulation of certain fats (triglycerides) inside liver cells. People with fatty liver may feel tired or have mild abdominal discomfort but otherwise have no symptoms... read more , and liver scarring (cirrhosis Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more ). An alcohol-damaged liver is less able to rid the body of toxic waste products, which can cause brain dysfunction (hepatic encephalopathy Hepatic Encephalopathy Hepatic encephalopathy is deterioration of brain function that occurs in people with severe liver disease because toxic substances normally removed by the liver build up in the blood and reach... read more ). People developing hepatic encephalopathy become dull, sleepy, stuporous, and confused and may lapse into a coma. Hepatic coma is life threatening and needs to be treated immediately.

Usually, people with liver failure also have liver flap (asterixis Hepatic Encephalopathy Hepatic encephalopathy is deterioration of brain function that occurs in people with severe liver disease because toxic substances normally removed by the liver build up in the blood and reach... read more ). When the arms and hands are outstretched, the hands suddenly drop, then resume their original position. Liver flap resembles but is not a tremor.

Cirrhosis of the liver Cirrhosis of the Liver Cirrhosis is the widespread distortion of the liver's internal structure that occurs when a large amount of normal liver tissue is permanently replaced with nonfunctioning scar tissue. The scar... read more causes pressure to build up in the blood vessels around the liver (portal hypertension Portal Hypertension Portal hypertension is abnormally high blood pressure in the portal vein (the large vein that brings blood from the intestine to the liver) and its branches. Cirrhosis (scarring that distorts... read more ). Built up pressure in these blood vessels can cause swelling of blood vessels in the stomach and esophagus (varices). These swollen vessels can rupture and bleed heavily, causing people to vomit blood. This bleeding is a particular problem because the damaged liver does not produce enough of the substances that make blood clot.

Inflammation of the pancreas (pancreatitis Acute Pancreatitis Acute pancreatitis is sudden inflammation of the pancreas that may be mild or life threatening but usually subsides. Gallstones and alcohol abuse are the main causes of acute pancreatitis. Severe... read more ) can be caused by excessive alcohol use. People develop severe abdominal pain with vomiting.

Damage to the nerves and parts of the brain also can be caused by excessive alcohol use. When the nerves to the arms and legs (peripheral nerves Overview of the Peripheral Nervous System The peripheral nervous system refers to the parts of the nervous system that are outside the central nervous system, that is, those outside the brain and spinal cord. Thus, the peripheral nervous... read more ) are affected, people may have loss of sensation or feel pins and needles in their hands and feet. People may develop a chronic tremor Tremor A tremor is an involuntary, rhythmic, shaking movement of part of the body, such as the hands, head, vocal cords, trunk, or legs. Tremors occur when muscles repeatedly contract and relax. (See... read more . Damage to the part of the brain that coordinates movement (cerebellum) can lead to poorly controlled movement of the arms and legs and affect balance. Heavy long-term alcohol use can result in irreversible brain damage and psychosis. It can also damage the lining (myelin sheath) of nerves in the brain, resulting in a rare disorder called Marchiafava-Bignami disease. People with this disorder become agitated, confused, and demented. Some develop seizures and go into a coma before dying.

A severe deficiency of thiamin Thiamin Deficiency Thiamin deficiency (causing beriberi and other problems) is most common among people whose diet mainly consists of white rice or highly processed carbohydrates in countries with high rates of... read more , a B vitamin, can be caused by heavy long-term use of alcohol. This deficiency can lead to Wernicke encephalopathy Wernicke Encephalopathy Wernicke encephalopathy is a brain disorder that causes confusion, eye problems, and loss of balance and results from thiamin deficiency. Wernicke encephalopathy is caused by a severe deficiency... read more (a condition characterized by confusion, inability to coordinate while walking, or difficulty coordinating movement of the eyes), which, if not promptly treated, may result in Korsakoff syndrome Korsakoff Psychosis Korsakoff psychosis is a complication of long-term thiamin deficiency and causes memory loss for recent events, confusion, and behavioral changes. It is frequently diagnosed along with Wernicke... read more , coma Coma and Impaired Consciousness , or even death.

Existing depression Depression A short discussion of prolonged grief disorder. Depression is a feeling of sadness and/or a decreased interest or pleasure in activities that becomes a disorder when it is intense enough to... read more may be worsened by drinking alcohol, and people with alcohol use disorder are more likely to become depressed than people who are not problem drinkers. Because alcohol-related disorders, especially binge drinking, often causes deep feelings of remorse during dry periods, people with alcohol use disorder are prone to suicide even when they are not drinking.

Severe problems in the developing fetus, including low birth weight, short body length, small head size, heart damage, muscle damage, and low intelligence or intellectual disability, can be caused by alcohol use in pregnant women. These effects are called the fetal alcohol syndrome Alcohol during pregnancy More than 50% of pregnant women take prescription or nonprescription (over-the-counter) drugs or use social drugs (such as tobacco and alcohol) or illicit drugs at some time during pregnancy... read more . Avoidance of alcohol is therefore recommended during pregnancy.

If people who drink continually for a period of time suddenly stop drinking, withdrawal symptoms are likely. For example, withdrawal can occur during hospitalization (for example, for elective surgery) because drinkers are unable to obtain alcohol.

Withdrawal symptoms vary from mild to severe. Severe untreated alcohol withdrawal can be fatal.

Mild to moderate withdrawal usually begins within 6 hours after drinking stops. Mild symptoms include tremor, headache, weakness, sweating, and nausea. Some people have seizures Seizure Disorders In seizure disorders, the brain's electrical activity is periodically disturbed, resulting in some degree of temporary brain dysfunction. Many people have unusual sensations just before a seizure... read more (called alcohol-related epilepsy or rum fits).

Alcohol-related hallucinosis may occur in heavy drinkers who stop drinking. They hear voices that seem accusatory and threatening, causing apprehension and terror. Alcohol-related hallucinosis may last for days and can be controlled with antipsychotic medications, such as chlorpromazine or thioridazine.

Delirium tremens (DTs) is the most serious group of withdrawal symptoms. Usually, delirium tremens does not begin immediately. Rather, it appears about 48 to 72 hours after the drinking stops. People are initially anxious. Later, they become increasingly confused, do not sleep well, have frightening nightmares, sweat excessively, and become very depressed. The pulse rate speeds up and the blood pressure rises. Fever typically develops. The episode may escalate to include fleeting hallucinations, illusions that arouse fear and restlessness, and disorientation with visual hallucinations that may be terrifying. Objects seen in dim light may be particularly terrifying, and the people become extremely confused. Their balance is impaired, sometimes making them think the floor is moving, the walls are falling, or the room is rotating. As the delirium progresses, a persistent tremor develops in the hands and sometimes extends to the head and body. Most people become severely uncoordinated. Delirium tremens can be fatal, particularly when untreated.

Emergency treatment is needed when very large amounts of alcohol consumed or alcohol withdrawal causes moderate to severe symptoms.

There is no specific antidote for acute intoxication:

For alcohol withdrawal symptoms, doctors often prescribe a benzodiazepine (a mild sedative) for a few days. It reduces agitation and helps prevent some withdrawal symptoms, seizures, and delirium tremens. Because people can become dependent on benzodiazepines, these medications are used for only a short time. Antipsychotic medications Antipsychotic Drugs Psychosis refers to symptoms such as delusions, hallucinations, disorganized thinking and speech, and bizarre and inappropriate motor behavior that indicate loss of contact with reality. A number... read more are sometimes given to people with alcohol-related hallucinosis.

Delirium tremens can be life threatening and is treated aggressively to control the high fever and severe agitation. People are treated in an intensive care unit if possible. Treatment usually includes the following:

With such treatment, delirium tremens usually begins to clear within 12 to 24 hours of its beginning, but severe cases may last for 5 to 7 days. Most people do not remember events during severe withdrawal after it resolves.

After any urgent medical problems are resolved, further treatment depends on the severity of alcohol use and the person's other medical and mental health disorders. If people have not become dependent on alcohol, doctors may discuss the serious consequences of alcohol use with them, recommend ways to reduce or stop their drinking, and schedule follow-up visits to check on how well they are doing.

For people with more severe alcohol use, particularly those who have coexisting medical and mental health disorders, a detoxification and rehabilitation program may be recommended.

In the first phase of detoxification and rehabilitation, alcohol is completely withdrawn, and any withdrawal symptoms are treated. Then people with alcohol use disorder have to learn ways to modify their behavior. Without help, most problem drinkers relapse within a few days or weeks. Rehabilitation programs, which combine psychotherapy with medical supervision, can help. People are warned about how difficult stopping is. They are also taught ways to enhance the motivation to stop and to avoid situations that are likely to trigger drinking. Treatment is tailored to the individual. These programs also enlist the support of family members and friends. Self-help groups, such as Alcoholics Anonymous , can also help.

Sometimes certain medications (disulfiram, naltrexone, acamprosate, and clonidine) can help people with alcohol use disorder avoid drinking alcohol. However, medications can typically help only if people are motivated and cooperative and if the medications are used as part of an ongoing intensive counseling regimen. Results vary.

Disulfiram deters drinking because it interferes with alcohol metabolism, causing acetaldehyde (a substance that results from the breakdown of alcohol) to build up in the bloodstream. Acetaldehyde makes people feel ill. Within 5 to 15 minutes after people who took disulfiram drink alcohol, the buildup of acetaldehyde causes

Nausea and vomiting may follow 30 to 60 minutes later. These uncomfortable and potentially dangerous reactions last 1 to 3 hours.

The discomfort from drinking alcohol after taking disulfiram is so intense that few people risk drinking alcohol—even the small amount in some over-the-counter cough and cold preparations or some foods.

Disulfiram must be taken every day in order for it to be effective in stopping drinking.

The following people should not use disulfiram:

Naltrexone alters the effects of alcohol on certain chemicals made by the brain (endorphins), which may be associated with alcohol craving and consumption. This medication is effective in most people who take it consistently. A long-acting form can be given by injection once a month. Naltrexone, unlike disulfiram, does not make people sick. Thus, people taking naltrexone can continue to drink. Naltrexone should not be taken by people who have hepatitis Overview of Hepatitis Hepatitis is inflammation of the liver. (See also Overview of Acute Viral Hepatitis and Overview of Chronic Hepatitis.) Hepatitis is common throughout the world. Hepatitis can be Acute (short-lived) read more or certain other liver disorders.

Clonidine is a drug that affects certain parts of the brain and is typically used for high blood pressure but can help relieve some of the effects of alcohol withdrawal.