What happens when you drink alcohol?
When you drink alcohol, it is absorbed into the bloodstream from the stomach and intestines. All blood from the stomach and intestines first goes through the liver before circulating around the whole body. So, the highest concentration of alcohol is in the blood flowing through the liver.
Liver cells contain enzymes (chemicals) which process (metabolise) alcohol. The enzymes break down alcohol into other chemicals which in turn are then broken down into water and carbon dioxide. These are then passed out in the urine and from the lungs.
The liver cells can metabolise only a certain amount of alcohol per hour. So, if you drink alcohol faster than your liver can deal with it, the level of alcohol in your bloodstream rises.
What are the problems of drinking too much alcohol?
Your liver and body can usually cope with drinking a small amount of alcohol. Indeed, drinking a small amount of alcohol (1-2 units per day) may help to prevent heart disease and stroke. However, drinking over the recommended limits (detailed below) can be harmful. If you drink heavily you have an increased risk of developing:
- Serious liver problems (alcoholic liver disease).
- Some stomach disorders.
- Pancreatitis (severe inflammation of the pancreas).
- Mental health problems including depression and anxiety.
- Sexual difficulties such as impotence.
- Muscle and heart muscle disease.
- High blood pressure.
- Damage to nervous tissue.
- Accidents - drinking alcohol is associated with a much increased risk of accidents. In particular, injury and death from fire and car crashes. About 1 in 7 road deaths are caused by drinking alcohol.
- Some cancers (mouth, gullet, liver, colon and breast).
- Obesity (alcohol has many calories).
- Damage to an unborn baby in pregnant women.
- Alcohol dependence (addiction).
In the UK deaths due to alcohol related diseases (particularly liver disease) have risen considerably over the last 20 years or so. This is because heavy drinking and binge drinking have become more common.
The rest of this leaflet is about alcoholic liver disease. There are other leaflets in this series called 'Alcohol and Sensible Drinking' which deals with general aspects of alcohol, and 'Alcoholism and Problem Drinking' which includes information on alcohol dependence.
What is alcoholic liver disease?
Drinking too much alcohol can lead to three types of liver disease - fatty liver, hepatitis, and cirrhosis. Any, or all, of these conditions can occur at the same time in the same person.
Fatty liver
A build-up of fat occurs within liver cells in most people who regularly drink heavily. In itself, fatty liver is not usually serious and does not cause symptoms. Fatty liver will usually reverse if you stop drinking heavily. However, in some people the fatty liver progressess and develops into hepatitis.
Alcoholic hepatitis
Hepatitis means inflammation of the liver. The inflammation can range from mild to severe.
- Mild hepatitis may not cause any symptoms. The only indication of inflammation may be an abnormal level of liver enzymes in the blood which can be detected by a blood test. However, in some cases the hepatitis becomes persistent (chronic), which can gradually damage the liver and eventually cause cirrhosis.
- A more severe hepatitis tends to cause symptoms such as feeling sick, jaundice (yellowing of the skin caused by a high level of bilirubin - a chemical normally metabolised in the liver), generally feeling unwell, and sometimes pain over the liver.
- A very severe bout of alcoholic hepatitis can quickly lead to liver failure. This can cause deep jaundice, blood clotting problems, confusion, coma, bleeding into the guts, and is often fatal.
Alcoholic cirrhosis
Cirrhosis is a condition where normal liver tissue is replaced by scar tissue (fibrosis). The scarring tends to be a gradual process. The scar tissue affects the normal structure and regrowth of liver cells. Liver cells become damaged and die as scar tissue gradually develops. When this liver disease occurs the liver gradually loses its ability to function well. The scar tissue can also affect the blood flow through the liver which can cause 'back pressure' in the blood vessels which bring blood to the liver.
About 1 in 10 heavy drinkers will eventually develop cirrhosis. It tends to occur after 10 or more years of heavy drinking. Note: cirrhosis can develop in people who have never had alcoholic hepatitis.
Cirrhosis can happen from many causes other than alcohol. For example, persistent viral hepatitis and some hereditary and metabolic diseases. If you have another persistent liver disease, and drink heavily, you are likely to increase your risk of developing cirrhosis.
Cirrhosis can lead to end-stage liver disease ('liver failure'). However, in the early stages of the condition, often there are no symptoms. You can 'get by' with a reduced number of working liver cells. But, as more and more liver cells die, and more and more scar tissue builds up, symptoms start to appear. The eventual symptoms and complications are similar to a severe episode of hepatitis (listed above). However, unlike a bout of severe hepatitis, the symptoms and complications tend to develop slowly.
There is a separate leaflet called 'Cirrhosis' which gives more details.
It is not clear why some people are more prone for their liver cells to be damaged by alcohol and to develop hepatitis and/or cirrhosis. But, as a rule, the heavier you drink, and the more regularly that you drink, the more your risk of developing hepatitis and/or cirrhosis.
The scarring and damage of cirrhosis is usually permanent and cannot be reversed. However, recent research has led to a greater understanding of cirrhosis. Research suggests that it may be possible to develop medicines in the future which can reverse the scarring process of cirrhosis.
How is alcoholic liver disease diagnosed?
A doctor may suspect that you have liver problems from your symptoms, and a physical examination. (For example, they may detect that your liver is enlarged, or that you are retaining fluid.) They may especially think of liver disease as a cause of your symptoms if you have a history of heavy alcohol drinking. Some tests may be done.
- Blood tests may show abnormal liver function. (See separate page called 'Liver Function Tests' for details.)
- An ultrasound scan may show that you have a damaged liver.
- To confirm the diagnosis, a biopsy (small sample) of the liver may be taken to be looked at under the microscope. (See separate page called 'Liver Biopsy'.) The scarring of the liver caused by cirrhosis, or the typical features of liver cells with alcoholic hepatitis can be seen on a biopsy sample.
What is the treatment for alcoholic liver disease?
For all types of liver disease caused by alcohol, you should stop drinking completely. Also, you may be referred to a dietician to review your diet. This is because many people who drink heavily do not eat properly and need advice on getting back into eating a healthy diet. Vitamin supplements may be prescribed for a while.
- If you have fatty liver, or alcoholic hepatitis which is not severe, you should fully recover from these conditions if you stop drinking.
- If you have severe hepatitis and require hospital admission, you may require intensive care treatment. Some people with severe hepatitis will die.
- If you have cirrhosis, stopping drinking can improve your outlook. It depends on how severe the cirrhosis has become. If cirrhosis is diagnosed when it is not too advanced, and you stop drinking, the cirrhosis is unlikely to progress. However, the cirrhosis and symptoms will usually get worse if you continue to drink. In severe cases where the scarring is extensive, and the liver can barely function, then a liver transplant may be the only option.
There is a separate page called 'Cirrhosis'. This provides some details of the treatment of cirrhosis.
Preventing alcoholic liver disease
You are very unlikely to develop liver problems caused by alcohol if you drink within the recommended safe limits. That is:
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Men should drink no more than 21 units of alcohol per week (and no more than four units in any one day).
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Women should drink no more than 14 units of alcohol per week (and no more than three units in any one day).
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Pregnant women. The exact amount that is safe is not known. Therefore, advice from the Department of Health is that pregnant women and women trying to become pregnant should not drink at all. If you do chose to drink when you are pregnant then limit it to one or two units, once or twice a week. And never get drunk.
In general, the more you drink above the safe limits, the more harmful alcohol is likely to be. And remember, binge drinking can be harmful even though the weekly total may not seem too high. For example, if you only drink once or twice a week, but when you do you drink 4-5 pints of beer each time, or a bottle of wine each time, then this is a risk to your health.
One unit of alcohol is 10 ml (1 cl) by volume, or 8 g by weight, of pure alcohol. For example:
- One unit of alcohol is about equal to:
- half a pint of ordinary strength beer, lager, or cider (3-4% alcohol by volume), or
- a small pub measure (25 ml) of spirits (40% alcohol by volume), or
- a standard pub measure (50 ml) of fortified wine such as sherry or port (20% alcohol by volume).
- There are one and a half units of alcohol in:
- a small glass (125 ml) of ordinary strength wine (12% alcohol by volume), or
- a standard pub measure (35 ml) of spirits (40% alcohol by volume).
But remember, many wines and beers are stronger than the more traditional 'ordinary' strengths. A more accurate way of calculating units is as follows. The percentage alcohol by volume (%abv) of a drink equals the number of units in one litre of that drink. For example:
- Strong beer at 6% abv has six units in one litre. If you drink half a litre (500 ml) - just under a pint - then you have had three units.
- Wine at 14% abv has 14 units in one litre. If you drink a quarter of a litre (250 ml) - two small glasses - then you have had three and a half units.
Some other examples
Three pints of beer, three times per week, is at least 18-20 units per week. That is nearly the upper weekly safe limit for a man. However, each drinking session of three pints is at least six units, which is more than the safe limit advised for any one day. Another example: a 750 ml bottle of 12% wine contains nine units. If you drink two bottles of 12% wine over a week, that is 18 units. This is above the upper safe limit for a woman.
But, you should not drink alcohol at all if:
- You have already developed early cirrhosis.
- You have chronic hepatitis or certain other liver problems. Your doctor will advise for each specific condition.
Do you need help to stop drinking?
Help and treatment is available if you find that you cannot stop drinking. Counselling and support from a doctor, nurse, or counsellor is often all that is needed. A 'detoxification' treatment may be advised if you are alcohol dependent. Referral for specialist help may be best for some people. See a separate page called 'Alcoholism and Problem Drinking'.
If you feel that you, or a relative or friend, needs help about alcohol then see your doctor or practice nurse. Or, contact one of the agencies listed below.
Drinkline - National Alcohol Helpline
Tel: 0800 917 8282
Offers help to callers worried about their own drinking and support to the family and friends of people who are drinking. Advice to callers on where to go for help.
Alcoholics Anonymous
PO Box 1, 10 Toft Green, York, YO1 7ND
Helpline: 0845 769 7555 Web: www.alcoholics-anonymous.org.uk
There are over 3000 meetings held in the UK each week with over 40,000 members. The only requirement for membership is a desire to stop drinking.
AL-Anon Family Groups
61 Great Dover Street, London, SE1 4YF
Tel: 020 7403 0888 Web: www.al-anonuk.org.uk
Offers support for families and friends of alcoholics whether the drinker is still drinking or not.
Further information
British Liver Trust
2 Southampton Road Ringwood BH24 1HY
Tel: 0870 770 8028 Web: www.britishlivertrust.org.uk
References
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CKS Topic Review Alcohol - Problem Drinking (2007)
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I J Beckingham and S D Ryder ABC of diseases of liver, pancreas, and biliary system: Investigation of liver and biliary disease BMJ 2001;322:33-36.
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J E J Krige and I J Beckingham ABC of diseases of liver, pancreas, and biliary system: Portal hypertension1: varices BMJ 2001;322:348-351
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John P Iredale Cirrhosis: new research provides a basis for rational and targeted treatments BMJ 2003;327:143-147
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Madhotra R, Gilmore IT; Recent developments in the treatment of alcoholic hepatitis. QJM. 2003 Jun;96(6):391-400. [abstract]
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Wolf DC Cirrhosis eMedicine February 2007.
© EMIS and PiP 2007 Updated: 18 Jun 2007 DocID: 4395 Version: 38
