Alcoholic liver disease in the context of "Non-alcoholic steatohepatitis"

Alcohol, sometimes referred to by the chemical name ethanol, is the active ingredient in alcoholic drinks such as beer, wine, and distilled spirits (hard liquor). Alcohol is a central nervous system (CNS) depressant, decreasing electrical activity of neurons in the brain, which causes the characteristic effects of alcohol intoxication ("drunkenness"). Among other effects, alcohol produces euphoria, decreased anxiety, increased sociability, sedation, and impairment of cognitive, memory, motor, and sensory function.

Alcohol has a variety of adverse effects. Short-term adverse effects include generalized impairment of neurocognitive function, dizziness, nausea, vomiting, and symptoms of hangover. Alcohol is addictive and can result in alcohol use disorder, dependence, and withdrawal upon cessation. The long-term effects of alcohol are considered to be a major global public health issue and include liver disease, hepatitis, cardiovascular disease (e.g., cardiomyopathy), polyneuropathy, alcoholic hallucinosis, long-term impact on the brain (e.g., brain damage, dementia, and Marchiafava–Bignami disease), and cancers; alcohol and some of its metabolites (such as acetaldehyde) are IARC group 1 carcinogens. The adverse effects of alcohol on health are most significant when it is used in excessive quantities or with heavy frequency. However, in 2023, the World Health Organization published a statement in The Lancet Public Health that concluded, "no safe amount of alcohol consumption for cancers and health can be established." In high amounts, alcohol may cause loss of consciousness or, in severe cases, death. Many governmental agencies and organizations issue alcohol consumption recommendations.

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer in adults and is currently the most common cause of death in people with cirrhosis. HCC is the third leading cause of cancer-related deaths worldwide.

HCC most commonly occurs in those with chronic liver disease especially those with cirrhosis or fibrosis, which occur in the setting of chronic liver injury and inflammation. HCC is rare in those without chronic liver disease. Chronic liver diseases which greatly increase the risk of HCC include hepatitis infection such as (hepatitis B, C or D), non-alcoholic steatohepatitis (NASH), alcoholic liver disease, or exposure to toxins such as aflatoxin, or pyrrolizidine alkaloids. Certain diseases, such as hemochromatosis and alpha 1-antitrypsin deficiency, markedly increase the risk of developing HCC. The five-year survival in those with HCC is 18%.

Fatty liver disease (FLD), also known as hepatic steatosis and steatotic liver disease (SLD), is a condition where excess fat builds up in the liver. Often there are no or few symptoms. Occasionally there may be tiredness or pain in the upper right side of the abdomen. Complications may include cirrhosis, liver cancer, and esophageal varices.

The main subtypes of fatty liver disease are metabolic dysfunction–associated steatotic liver disease (MASLD, formerly "non-alcoholic fatty liver disease" (NAFLD)) and alcoholic liver disease (ALD), with the category "metabolic and alcohol associated liver disease" (metALD) describing an overlap of the two.

Fatty liver disease (FLD), also known as hepatic steatosis and steatotic liver disease (SLD), is a condition where excess fat builds up in the liver. Often there are no or few symptoms. Occasionally there may be tiredness or pain in the upper right side of the abdomen. Complications may include cirrhosis, liver cancer, and esophageal varices.

The main subtypes of fatty liver disease are metabolic dysfunction–associated steatotic liver disease (MASLD) and alcoholic liver disease (ALD), with the category "metabolic and alcohol associated liver disease" (metALD) describing an overlap of the two.

The long-term effects of alcohol consumption on health are predominantly detrimental, with the severity and range of harms generally increasing with the cumulative amount of alcohol consumed over a lifetime. The extent of these effects varies depending on several factors, including the quantity and frequency of alcohol intake, as well as individual genetic and lifestyle factors. Alcohol is recognized as a direct cause of several diseases, including cancer. The International Agency for Research on Cancer (IARC) classifies alcohol as a Group 1 carcinogen, meaning it is capable of causing cancer in humans. Research shows a causal link between alcohol consumption and at least seven types of cancer, including cancers of the oropharynx (mouth and throat), esophagus, liver, colorectum, and female breast. The risk begins with any level of consumption and goes up with higher intake—even light or moderate drinking adds to the risk. No level of alcohol consumption has been identified as completely safe in terms of cancer risk. The biological mechanisms include the damage caused by acetaldehyde, a toxic byproduct of alcohol metabolism, which can alter DNA, and the generation of oxidative stress.

Beyond cancer, chronic and excessive alcohol use—as seen in alcohol use disorder—is capable of damaging nearly every part of the body. Such use is linked to alcoholic liver disease, which can progress to cirrhosis and chronic pancreatitis; various forms of cardiovascular disease, including hypertension, coronary heart disease, heart failure, and atrial fibrillation; and digestive conditions such as gastritis and stomach ulcers. Alcohol also interferes with how the body absorbs nutrients, which can lead to malnutrition. Long-term use can cause alcohol-related dementia and damage to the peripheral nervous system, leading to conditions like painful peripheral neuropathy. Drinkers are also more likely to get injured in accidents, including traffic accidents and falls, and may age faster.

Alcoholic hepatitis is hepatitis (inflammation of the liver) due to excessive intake of alcohol. Patients typically have a history of at least 10 years of heavy alcohol intake, typically 8–10 drinks per day. It is usually found in association with fatty liver, an early stage of alcoholic liver disease, and may contribute to the progression of fibrosis, leading to cirrhosis. Symptoms may present acutely after a large amount of alcoholic intake in a short time period, or after years of excess alcohol intake. Signs and symptoms of alcoholic hepatitis include jaundice (yellowing of the skin and eyes), ascites (fluid accumulation in the abdominal cavity), fatigue and hepatic encephalopathy (brain dysfunction due to liver failure). Mild cases are self-limiting, but severe cases have a high risk of death. Severity in alcoholic hepatitis is determined several clinical prediction models such as the Maddrey's Discriminant Function and the MELD score.

Severe cases may be treated with glucocorticoids with a response rate of about 60%. The condition often comes on suddenly and may progress in severity very rapidly.

In a 2018 study on 599,912 drinkers, a roughly linear association was found with alcohol consumption and a higher risk of stroke, coronary artery disease excluding myocardial infarction, heart failure, fatal hypertensive disease, and fatal aortic aneurysm, even for moderate drinkers. Alcohol abuse may also cause occupational cardiovascular disease. The American Heart Association states that people who are currently non-drinkers should not start drinking alcohol.

Excessive alcohol intake is associated with an elevated risk of alcoholic liver disease (ALD), heart failure, some cancers, and accidental injury, and is a leading cause of preventable death in industrialized countries. Some studies have suggested that one drink per day may have cardiovascular benefits. However, these studies are controversial, and the common view is that no level of alcohol consumption improves health. There is far more evidence for the harmful effects of alcohol than for any beneficial effects. It is also recognized that the alcohol industry may promote the unsubstantiated benefits of moderate drinking.