Since the mutation is a genetic issue, there is currently no cure for the flush reaction. Clinicians and the East Asian public generally know about the alcohol flushing response. Prevention would include not drinking alcohol.

Individuals who experience the alcohol flushing reaction may be less prone to alcoholism. Disulfiram, a drug sometimes given as treatment for alcoholism, works by inhibiting acetaldehyde dehydrogenase, causing a five to tenfold increase in the concentration of acetaldehyde in the body. The resulting irritating flushing reaction tends to discourage affected individuals from drinking.

For measuring the level of flush reaction to alcohol, the most accurate method is to determine the level of acetaldehyde in the blood stream. This can be measured through both a breathalyzer test or a blood test. Additionally, measuring the amount of alcohol metabolizing enzymes alcohol dehydrogenases and aldehyde dehydrogenase through genetic testing can predict the amount of reaction that one would have. More crude measurements can be made through measuring the amount of redness in the face of an individual after consuming alcohol. Computer and phone applications can be used to standardize this measurement.

Other effects include "nausea, headache and general physical discomfort".

Many cases of alcohol-induced respiratory reactions, which involve rhinitis and worsening of asthma, develop within 1–60 minutes of drinking alcohol and are due to the same causes as flush reactions.

Diagnosis of alcohol-induced respiratory symptoms can be strongly suggested on the bases of survey questionnaires. Questionnaires can be devised to determine the specific types of alcoholic beverages eliciting reactions; reactions evoked by one or only a few but not other types of alcoholic beverage, particularly when the offending beverage(s) is wine and/or beer, suggest that the reactions are due to classical allergic reaction to allergens in the beverage; reactions to all or most types of alcoholic beverages favors a genetic (i.e. acetaldehyde-induce) basis. Further differentiation between these two causes can be tested under medical supervision be determining if ingestion of a water-diluted pure ethanol solution elicits reactions or if an offending alcoholic beverage but not the same beverage without ethanol elicits reactions. Either result would favor an acetaldehyde-induced genetic basis for the reaction.

Diagnosis of alcohol sensitivity due to the accumulation of acetaldehyde in individuals bearing the glu487lys ALDH2 allele can be made by measuring the diameter of the erythema (i.e. red) area developing under a 15 millimeter skin patch plaster soaked in 70% ethanol and applied for 48 hours (ethanol patch test); erythema of 15 millimeters is considered positive with a false positive ratio ([100 x {number of individuals with a positive patch test}]/{number of individuals with a normal ALDH2 genotype}) of 5.9% and a false negative ratio ([100 x {number of individuals with a negative patch test}]/{number of individuals with a glu487lys ALDH2 allele}) of 0%. To resolve ambiguities in or replace the ethanol patch test for other reasons, a polymerase chain reaction using special primers and conditions can be used to directly detect the glu487lys ALDH2 genes. For other causes of acetaldehyde-induced alcohol sensitivities, the ethanol patch test will need to be tested for verification of its acetaldehyde basis and appropriate polymerase chain reactions will likewise be needed to verify a genetic basis for symptoms.

Diagnosis of alcohol sensitivity due to allergic reactivity to the allergens in alcoholic beverages can be confirmed by standard skin prick tests, skin patch tests, blood tests, challenge tests, and challenge/elimination tests as conducted for determining the allergen causing other classical allergic reactions (see allergy and Skin allergy tests.)

Avoidance of ethanol is the safest, surest, and cheapest treatment. Indeed, surveys find a positive correlation between high incidences of glu487lys ALDH2 allele-related alcohol-induced respiratory reactions as well as other causes of these reactions and low levels of alcohol consumption, alcoholism, and alcohol-related diseases. Evidently, people suffering these reaction self-impose avoidance behavior. There is a proviso here: ethanol, at surprisingly high concentrations, is used as a solvent to dissolve many types of medicines and other ingredients. This pertains particularly to liquid cold medicines and mouthwashes. Ethanol avoidance includes avoiding the ingestion of and, depending on an individual's history, mouth washing with, such agents.

Type H1 antagonists in the histamine antagonist family of drugs were tested in Japanese volunteers with alcohol-induced asthma (who presumably have glu487lys ALDH2 allele-associated asthma) and found to be completely effective in blocking bronchoconstriction responses to alcoholic beverages; these blockers, it is suggested, may be taken 1–2 hours before consumption of alcohol beverages as a preventative of alcohol-induced respiratory reactions. In the absence of specific studies on the prevention of classical alcohol induced rhinitis and asthma due to allergens in alcoholic beverages, see asthma section on Prevention and rhinitis section on Prevention of allergen-induced reactions.

In the absence of specific studies on the treatment of acute alcohol-induced bronchoconstriction and rhinitis, treatment guidelines should probably follow those of their comparable allergen-induced classical allergic reactions (see asthma section on Treatment and rhinitis section on Treatment) but possibly favoring the testing of H1 antagonist anti-histamines as part of the initial protocol.

Definitive diagnosis relies on a blood test for alcohol, usually performed as part of a toxicology screen.

Law enforcement officers in the United States of America often use breathalyzer units and field sobriety tests as more convenient and rapid alternatives to blood tests.

There are also various models of breathalyzer units that are available for consumer use. Because these may have varying reliability and may produce different results than the tests used for law-enforcement purposes, the results from such devices should be conservatively interpreted.

Many informal intoxication tests exist, which, in general, are unreliable and not recommended as deterrents to excessive intoxication or as indicators of the safety of activities such as motor vehicle driving, heavy equipment operation, machine tool use, etc.

For determining whether someone is intoxicated by alcohol by some means other than a blood-alcohol test, it is necessary to rule out other conditions such as hypoglycemia, stroke, usage of other intoxicants, mental health issues, and so on. It is best if his/her behavior has been observed while the subject is sober to establish a baseline. Several well-known criteria can be used to establish a probable diagnosis. For a physician in the acute-treatment setting, acute alcohol intoxication can mimic other acute neurological disorders, or is frequently combined with other recreational drugs that complicate diagnosis and treatment.

Different countries recommend different maximum quantities. For most countries, the maximum quantity for men is 140 g–210 g per week. For women, the range is 84 g–140 g per week. Most countries recommend total abstinence during pregnancy and lactation.

There are reliable tests for the actual use of alcohol, one common test being that of blood alcohol content (BAC). These tests do not differentiate alcoholics from non-alcoholics; however, long-term heavy drinking does have a few recognizable effects on the body, including:

- Macrocytosis (enlarged MCV)

- Elevated GGT

- Moderate elevation of AST and ALT and an AST: ALT ratio of 2:1

- High carbohydrate deficient transferrin (CDT)

With regard to alcoholism, BAC is useful to judge alcohol tolerance, which in turn is a sign of alcoholism.

However, none of these blood tests for biological markers is as sensitive as screening questionnaires.

Hippuric acid has long been used as an indicator of toluene exposure; however, there appears to be some doubt about its validity. There is significant endogenous hippuric acid production by humans; which shows inter- and intra-individual variation influenced by factors such as diet, medical treatment, alcohol consumption, etc. This suggests that hippuric acid may be an unreliable indicator of toluene exposure. It has been suggested that urinary hippuric acid, the traditional marker of toluene exposure is simply not sensitive enough to separate the exposed from the non-exposed. This has led to the investigation of other metabolites as markers for toluene exposure.

Urinary "o"-cresol may be more reliable for the biomonitoring of toluene exposure because, unlike hippuric acid, "o"-cresol is not found at detectable levels in unexposed subjects. o-Cresol may be a less sensitive marker of toluene exposure than hippuric acid. o-Cresol excretion may be an unreliable method for measuring toluene exposure because o-cresol makes up <1% of total toluene elimination.

Benzylmercapturic acid, a minor metabolite of toluene, is produced from benzaldehyde. In more recent years, studies have suggested the use of urinary benzylmercapturic acid as the best marker for toluene exposure, because: it is not detected in non-exposed subjects; it is more sensitive than hippuric acid at low concentrations; it is not affected by eating or drinking; it can detect toluene exposure down to approximately 15 ppm; and it shows a better quantitative relationship with toluene than hippuric acid or "o"-cresol.

Medical organizations strongly discourage drinking alcohol during pregnancy. Alcohol passes easily from the mother's bloodstream through the placenta and into the bloodstream of the fetus, which interferes with brain and organ development. Alcohol can affect the fetus at any stage during pregnancy, but the level of risk depends on the amount and frequency of alcohol consumed. Regular heavy drinking and binge drinking (four or more drinks on any one occasion) pose the greatest risk for harm, but lesser amounts can cause problems as well. There is no known safe amount or safe time to drink during pregnancy.

Prenatal alcohol exposure can lead to fetal alcohol spectrum disorders (FASDs). The most severe form of FASD is fetal alcohol syndrome (FAS). Problems associated with FASD include facial anomalies, low birth weight, stunted growth, small head size, delayed or uncoordinated motor skills, hearing or vision problems, learning disabilities, behavior problems, and inappropriate social skills compared to same-age peers. Those affected are more likely to have trouble in school, legal problems, participate in high-risk behaviors, and develop substance use disorders themselves.

While little detailed genetic research has been done, it has been shown that alcoholism tends to run in families with possible involvement of differences in alcohol metabolism and the genotype of alcohol-metabolizing enzymes.

The World Health Organization, the European Union and other regional bodies, national governments and parliaments have formed alcohol policies in order to reduce the harm of alcoholism. Targeting adolescents and young adults is regarded as an important step to reduce the harm of alcohol abuse. Increasing the age at which licit drugs of abuse such as alcohol can be purchased, the banning or restricting advertising of alcohol has been recommended as additional ways of reducing the harm of alcohol dependence and abuse. Credible, evidence based educational campaigns in the mass media about the consequences of alcohol abuse have been recommended. Guidelines for parents to prevent alcohol abuse amongst adolescents, and for helping young people with mental health problems have also been suggested.

Over-consumption of alcohol causes many deaths worldwide. The overall mortality from alcohol use was found to be similar to that of the effect of physical inactivity. A review in 2009 found that "the net effect of alcohol consumption on health is detrimental, with an estimated 3.8% of all global deaths and 4.6% of global disability-adjusted life-years attributable to alcohol."

Extensive research of Western cultures has consistently shown increased survival associated with light to moderate alcohol consumption. A 23-year prospective study of 12,000 male British physicians aged 48–78, found that overall mortality was significantly lower in current drinkers compared to non-drinkers even after correction for ex-drinkers. This benefit was strongest for ischemic heart disease, but was also noted for other vascular disease and respiratory disease. Death rate amongst current drinkers was higher for 'alcohol augmentable' disease such as liver disease and oral cancers, but these deaths were much less common than cardiovascular and respiratory deaths. The lowest mortality rate was found for consumption of 8 to 14 'units' per week. In the UK a unit is defined as 10ml or 8g of pure alcohol. Higher consumption increased overall mortality rate, but not above that of non-drinkers. Other studies have found age-dependent mortality risks of low-to-moderate alcohol use: an increased risk for individuals aged 16–34 (due to increased risk of cancers, accidents, liver disease, and other factors), but a decreased risk for individuals ages 55+ (due to lower incidence of ischemic heart disease).

This is consistent with other research that found a J-curve dependency between alcohol consumption and total mortality among middle aged and older men. While the mortality rates of ex-drinkers and heavy drinkers are significantly elevated, the all-cause mortality rates may be 15-18% lower among moderate drinkers. Although the definition of a drink varies between studies and countries, this meta-analysis found that low levels of alcohol intake, defined as 1-2 drinks per day for women and 2-4 drinks per day for men, was associated with lower mortality than abstainers. This claim was challenged by another study that found that in certain low quality studies occasional drinkers or ex-drinkers were included as abstainers, resulting in the increased mortality in that group. However, the J-curve for total and CHD mortality was reconfirmed by studies that took the mentioned confounders into account. There seems to be little discussion of what proportion of individuals classified as abstainers are those already at greater risk of mortality due to chronic conditions and do not or cannot consume alcohol for reasons of health or harmful interactions with medication.

The observed decrease in mortality of light-to-moderate drinkers compared to never drinkers might be partially explained by superior health and social status of the drinking group; however, the protective effect of alcohol in light to moderate drinkers remains significant even after adjusting for these confounders. Additionally, confounders such as underreporting of alcohol intake might lead to the underestimation of how much mortality is reduced in light-to-moderate drinkers.

A 2010 study confirmed the beneficial effect of moderate alcohol consumption on mortality. Subjects were grouped into abstainers, light, moderate, and heavy drinkers. The order of mortality rates from lowest to highest were moderate, light, heavy, and abstainers. The increased risk for abstainers was twice the mortality rate as for moderate drinkers. This study specifically sought to control for confounding factors including the problem of ex-drinkers considered as non-drinkers. According to another study, drinkers with heavy drinking occasions (six or more drinks at a time) have a 57% higher all-cause mortality than drinkers without heavy drinking occasions.

Mortality is lowest among young abstainers and highest among young heavy drinkers.

In contrast to studies of Western cultures, research in other cultures has yielded some opposite findings. The landmark INTERHEART Study has revealed that alcohol consumption in South Asians was not protective against CAD in sharp contrast to other populations who benefit from it. In fact Asian Indians who consume alcohol had a 60% higher risk of heart attack which was greater with local spirits (80%) than branded spirits (50%). The harm was observed in alcohol users classified as occasional as well as regular light, moderate, and heavy consumers.

Another large study of 4465 subjects in India also confirmed the possible harm of alcohol consumption on coronary risk in men. Compared to lifetime abstainers, alcohol users had higher blood sugar (2 mg/dl), blood pressure (2 mm Hg) levels, and the HDL-C levels (2 mg/dl) and significantly higher tobacco use (63% vs. 21%).

Many countries collect statistics on alcohol-related deaths. While some categories relate to short-term effects, such as accidents, many relate to long-term effects of alcohol.

RWH could be caused by the release of prostaglandins which some people are not able to metabolize. Prostaglandins are substances that can contribute to pain and swelling. Ibuprofen (Advil), paracetamol (Tylenol) and aspirin are prostaglandin inhibitors. Aspirin and ibuprofen were shown to be effective at blocking both early and late stages of the RWH, and paracetamol (acetaminophen) was effective in blocking the early stage. However, combining paracetamol/acetaminophen and/or NSAIDs (like ibuprofen) with alcohol are not good for the liver, and can be potentially harmful. Some individuals will experience extreme nausea, vomiting, and abdominal pain when combining alcohol with acetaminophen and/or NSAIDs. The combination should never be used.

The Alcohol Use Disorders Identification Test (AUDIT) is considered the most accurate alcohol screening tool for identifying potential alcohol misuse, including dependence. It was developed by the World Health Organisation, designed initially for use in primary healthcare settings with supporting guidance.

Tyramine may well be a major player in RWH syndrome. Tyramine is an amine that is produced naturally from the breakdown of protein as food ages. More specifically it is formed by the decarboxylation of the amino acid tyrosine. It is found in aged, fermented, and spoiled foods. Everyday foods we consume including aged cheeses, overripe and dried fruit, sauerkraut, soy, and many processed foods contain high levels of tyramine. Tyramine is suspected of inducing migraine headaches in about 40% of migraine sufferers, according to F.G.Freitag of Diamond Headache Clinic in Chicago.

The tolerance to alcohol is not equally distributed throughout the world's population, and genetics of alcohol dehydrogenase indicate resistance has arisen independently in different cultures. In North America, Native Americans have the highest probability of developing alcoholism compared to Europeans and Asians.

Higher body masses and the prevalence of high levels of alcohol dehydrogenase in an individual increase alcohol tolerance.

Not all differences in tolerance can be traced to biochemistry. Differences in tolerance levels are also influenced by socio-economic and cultural difference including diet, average body weight and patterns of consumption.

An estimated one out of twenty people have an alcohol flush reaction. It is not in any way an indicator for the drunkenness of an individual. It is colloquially known as "face flush", a condition where the body metabolizes alcohol nearly 100-times less efficiently into acetaldehyde, a toxic metabolite. Flushing, or blushing, is associated with the erythema (reddening caused by dilation of capillaries) of the face, neck, and shoulder, after consumption of alcohol.

The Alcohol Use Disorders Identification Test (AUDIT) is considered the most accurate alcohol screening tool for identifying potential alcohol misuse, including dependence. It was developed by the World Health Organisation, designed initially for use in primary healthcare settings with supporting guidance.

AUDIT has replaced older screening tools such as CAGE but there are many shorter alcohol screening tools, mostly derived from the AUDIT. The Severity of Alcohol Dependence Questionnaire (SAD-Q) is a more specific twenty-item inventory for assessing the presence and severity of alcohol dependence.

A normal liver detoxifies the blood of alcohol over a period of time that depends on the initial level and the patient's overall physical condition. An abnormal liver will take longer but still succeeds, provided the alcohol does not cause liver failure.

People having drunk heavily for several days or weeks may have withdrawal symptoms after the acute intoxication has subsided.

A person consuming a dangerous amount of alcohol persistently can develop memory blackouts and idiosyncratic intoxication or pathological drunkenness symptoms.

Long-term persistent consumption of excessive amounts of alcohol can cause liver damage and have other deleterious health effects.

Research has shown that moderate levels of alcohol consumed with meals does not have a substantial impact on blood sugar levels. A 2005 study presented to the American Diabetes Association suggest that moderate consumption may lower the risk of developing Type 2 diabetes.

The International Agency for Research on Cancer of the World Health Organization has classified alcohol as a Group 1 carcinogen.

Preventing or reducing the harm has been called for via increased taxation of alcohol, stricter regulation of alcohol advertising and the provision of brief Interventions. Brief Interventions for alcohol abuse reduce the incidence of unsafe sex, sexual violence, unplanned pregnancy and, likely, STD transmission. Information and education on social norms and the harms associated with alcohol abuse delivered via the internet or face-to-face has not been found to result in any meaningful benefit in changing harmful drinking behaviours in young people.

According to European law, individuals who are suffering from alcohol abuse or other related problems cannot be given a license, or if in possession of a license cannot get it renewed. This is a way to prevent individuals driving under the influence of alcohol, but does not prevent alcohol abuse per se.

An individual's need for alcohol can depend on their family's alcohol use history. For instance, if it is discovered that their family history with alcohol has a strong pattern, there might be a need for education to be set in place to reduce the likelihood of reoccurrence (Powers, 2007). However, studies have established that those with alcohol abuse tend to have family members who try to provide help. In many of these occasions the family members would try to help the individual to change or to help improve the individual's lifestyle.

An alcohol enema, also known colloquially as butt-chugging, is the act of introducing alcohol into the rectum and colon via the anus. This method of alcohol consumption can be dangerous and even deadly because it leads to faster intoxication since the alcohol is absorbed directly into the bloodstream and neutralizes the body's ability to reject the toxin by vomiting.

In Northern Australia, where ciguatera is a common problem, two different folk science methods are widely believed to detect whether fish harbor significant ciguatoxin. The first method is that flies are supposed not to land on contaminated fish. The second is that cats will either refuse to eat or vomit/display symptoms after eating contaminated fish. A third, less common testing method involves putting a silver coin under the scales of the suspect fish. If the coin turns black, according to the theory, it is contaminated.

On Grand Cayman and other islands the locals will test barracuda by placing a piece of the fish on the ground and allowing ants to crawl on it. If the ants do not avoid the flesh and will eat it, then the fish is deemed safe.

In Dominican Republic, another common belief is that during months whose names do not include the letter "R" (May through August), it is not recommended to eat certain kinds of fish, because they are more likely to be infected by the ciguatera toxin.

The validity of many of these tests has been scientifically rejected.

Many hospitals use the Clinical Institute Withdrawal Assessment for Alcohol (CIWA) protocol in order to assess the level of withdrawal present and therefore the amount of medication needed. When overuse of alcohol is suspected but drinking history is unclear, testing for elevated values of carbohydrate-deficient transferrin or gammaglutamyl transferase can help make the diagnosis of alcohol overuse and dependence more clear. The CIWA has also been shortened (now called the CIWA-Ar), while retaining its validity and reliability, to help assess patients more efficiently due to the life-threatening nature of alcohol withdrawal.

Other conditions that may present similarly include benzodiazepine withdrawal syndrome (a condition also mainly caused by GABA receptor adaptation).