Gout is a common type of arthritis. The symptoms of gout include painful swelling and inflammation in one or more of the joints. Gout usually affects the big toe, but it can develop in any joint in the body.
Gout is caused by a build-up of uric acid in the body. Uric acid is a waste product that is produced during the process of metabolism (when the body breaks down food to use as energy). Usually, uric acid is excreted by the kidneys.
People whose kidneys do not excrete uric acid properly, or those who produce too much uric acid, can have high levels of uric acid in their blood. If the level becomes very high, crystals form in the joints. The crystals cause the joints to become inflamed and painful.
How common is gout?
Gout is one of the most common types of arthritis that affects men. It is estimated that 1% of all men in England will be affected by gout.
Gout can affect women, although men are three to four times more likely to develop it.
In men, the symptoms of gout usually begin between the ages of 40 and 60. In women, the symptoms begin later, usually between 60 and 80 years of age.
Risk factors for gout include:
- drinking alcohol (particularly beer)
- a diet that is high in purines (chemicals found in certain foods, such as red meat and seafood)
Treatment for gout involves relieving the symptoms of pain and trying to prevent further episodes. This is done using a combination of medication and lifestyle changes. See Treatment for gout for further information.
The outlook for gout is good as long as people use their medication as directed and make the recommended lifestyle changes, such as changing their diet and reducing their consumption of alcohol.
Over time, many people reduce their uric acid levels sufficiently so that they no longer experience any symptoms.
Symptoms of gout
It is difficult to predict when an attack of gout will occur. Symptoms can develop rapidly over a few hours and usually last for 3-10 days. After this time, the joint will start to feel normal again and any pain or discomfort should eventually disappear completely.
The primary symptom of gout is acute (sudden and severe) joint pain, usually in the joint of the big toe. Symptoms often develop during the night, although they can occur at any time. Other symptoms of gout include:
- red, shiny skin over the affected joint
- peeling, itchy and flaky skin over the affected joint
The intense pain that gout causes can make walking and getting around difficult. Even the light pressure of a bed cover or blanket can be painful.
Seventy per cent of people with gout experience their first gout attack in the big toe, and 90% of people with gout will experience pain in this joint at some point. However, while gout is most common in the big toe, it can affect any joint. It can also occur in two or more joints at the same time. Affected joints may include:
The sooner symptoms are treated, the more quickly the pain will pass. You may experience symptoms every few weeks, months or years, but it is impossible to predict when the condition will recur. Sixty-two per cent of people experience a repeat attack of gout within a year. However, some people only ever experience one attack in their lifetime.
Causes of gout
Gout is caused by a build-up of uric acid in the blood. Uric acid is a waste product that is usually harmless. It forms when the body breaks down chemicals in the cells known as purines.
Two-thirds of uric acid is produced by the kidneys. The other third is produced by the digestive system. Purines are found naturally in the body but they are also found in some foods and in beer.
Uric acid usually dissolves in your blood and passes through your kidneys into your urine so that it can be passed out of your body.
If you produce too much uric acid or remove too little through urinating, the uric acid will build up and may cause microscopic crystals to form. They usually form in a joint or surrounding tissue. These crystals trigger a reaction from your immune system, which causes the pain and inflammation associated with gout.
Some things can increase the amount of uric acid in your blood, making you more likely to develop gout. These risk factors fall into one of two categories:
- lifestyle factors, such as diet
- medical conditions that are known to increase levels of uric acid, such as high blood pressure (hypertension)
These risk factors are discussed in more detail below.
Men are three to four times more likely to develop gout than women. This is because their uric acid levels rise during puberty. During the menopause, women experience a similar, albeit smaller, rise in their uric acid levels. This explains why the onset of symptoms occurs later in women than it does in men.
Foods that are naturally high in purines include:
Alcoholic drinks raise the level of uric acid in the blood by increasing its production in the liver and by reducing how much is passed out in urine.
Beer and spirits do so more than wine, and beer also contains significant quantities of purines.
Certain types of medication can increase your uric acid levels and your risk of developing gout. These include:
- low-dose aspirin, which may be taken for a headache, for example (but very low doses, such as those taken to prevent heart attacks, do not have a noticeable effect)
- chemotherapy medications, which are used to treat cancer
- diuretics, which are used to treat high blood pressure (hypertension) or an abnormal build-up of fluid in your body
- niacin, which is used to treat high cholesterol
Studies have shown that gout often runs in families. Around 20% of people with gout have a close family member who also has the condition.
Medical conditions that can increase your risk of developing gout include:
- psoriasis, a condition that causes skin cells to reproduce too quickly, leading to red, flaky and crusty skin
- high blood pressure (hypertension)
- reduced kidney function, for example after a kidney transplant or if you have kidney failure
- hyperlipidaemia, high fat and cholesterol levels in your blood
- vascular disease, when your arteries become thickened, narrowed or blocked
Gout attacks occur most frequently in the joints of the feet and hands because the temperature in these joints is often lower than that in the rest of the body, which increases the likelihood of crystals forming.
When uric acid enters your bloodstream, it is carried by a substance called plasma. Plasma is the liquid part of your blood that is responsible for carrying proteins and chemicals. When plasma becomes cooler, the uric acid in your blood separates out from the plasma, allowing it to build up and form into crystals that cause the pain associated with gout.
It is still uncertain, however, why some people are more susceptible to crystal formation and gout than others with equally high blood levels of uric acid. Many people with a high level of uric acid in their blood and tissues never develop gout.
No single test or examination can be used to confirm a diagnosis of gout. Instead, your GP will look at your symptoms and medical history to make a diagnosis.
Many conditions can cause joint pain, inflammation and swelling. Gout is just one of over 200 different forms of arthritis (any condition that causes inflammation, pain and swelling in the joints).
Therefore, your GP may be unable to make a firm diagnosis straight away and you may have to be referred for further tests. The tests (explained below) will either help confirm the diagnosis of gout or rule out other conditions.
Serum uric acid
A serum uric acid test is usually carried out four to six weeks after an attack of gout, as the serum uric acid level is often not raised at the time of the attack.
During the test, a sample of blood will be taken from a vein in your arm. The blood sample will be analysed to measure the amount of uric acid in your blood.
A raised uric acid level is often a strong indication that you have developed gout. However, a serum uric acid test cannot definitively diagnose the condition. Some healthy people without gout have high uric acid levels in their blood, while others who experience an attack of gout have a normal uric acid level.
If there is any doubt about what is causing your joint pain, you may have a sample of synovial fluid taken from the affected joint. Synovial fluid helps to keep the joint lubricated and stops the bones and cartilage from rubbing against each other.
The fluid sample will be taken using a needle and syringe. It will then be examined under a microscope. If you have gout, there will usually be crystals of uric acid present in the sample. This sort of test will also help to rule out any form of infection that may be causing your symptoms, such as septic arthritis (when a joint becomes infected with bacteria).
An X-ray is rarely used to diagnose gout because the inflammation that gout causes is not usually detectable using this method. However, an X-ray is sometimes used to help rule out other conditions that affect the joints, such as chondrocalcinosis (a build-up of calcium crystals in the joints).
Confirming the diagnosis
As there is no single test to diagnose gout, a checklist is often used. This is based on the known pattern of symptoms that are associated with the condition. The list of criteria used is as follows:
- You have had more than one attack of the symptoms of pain, swelling and inflammation.
- You have experienced high levels of inflammation within one day of the onset of symptoms.
- The symptoms only affect one joint at a time.
- The joint in your big toe has been affected by symptoms.
- Other joints in your feet have been affected by symptoms.
- The results of the serum acid test show raised levels of uric acid in your blood.
- Physical examination or X-rays have detected swelling within a joint.
- There is no evidence that your joint has been infected by bacteria.
You will usually be diagnosed with gout if at least six of the statements above apply to you.
About four to six weeks after your gout attack has subsided, your GP may ask you to return for a follow-up appointment.
During the appointment, your GP will check your serum uric acid level to see if it is persistently raised.
They may also measure your blood pressure and check the status of any other conditions that you may have. Your GP will give you advice about lifestyle changes that will help minimise the risk of gout recurring.
Your GP can also give you an advance prescription of painkilling medication so that you can deal with attacks of gout promptly without having to wait to see your GP. See Treating gout for more information.
Your treatment plan
If you have gout, your treatment plan will have two goals:
- to relieve the symptoms of a gout attack
- to prevent further attacks from occurring
During a gout attack, it is important to rest, elevate (raise) your limb and avoid accidentally knocking or damaging the affected joint.
Keeping the affected joint cool should help improve your symptoms. To cool the joint, remove any clothing from around the joint and apply an ice pack. You can buy ice packs from a pharmacist, or you can use a bag of frozen peas or some ice wrapped inside a towel.
Apply the ice pack to your joint for approximately 20 minutes. Do not apply ice directly to your skin and do not apply it for more than 20 minutes at a time because this could damage the skin.
Non-steroidal anti-inflammatory drugs (NSAIDs) are a type of painkiller usually recommended as an initial treatment to relieve the symptoms of gout. NSAIDs work by reducing the levels of pain and inflammation. NSAIDs often used to treat the symptoms of gout include:
If you have been prescribed NSAIDs for gout, it is best to keep them near you at all times so that you can use them at the first sign of a gout attack. Continue to take your medication throughout the attack and for 48 hours after the attack has finished.
NSAIDs must be avoided in people with reduced kidney function and only used with great care under medical direction in patients who have had problems with indigestion, stomach ulcers or bleeding.
If you are unable or do not want to take NSAIDs, or if NSAIDs are ineffective at treating your symptoms, colchicine can be used instead. Colchicine works by interfering with the uric acid crystals to reduce inflammation.
While colchicine is usually an effective treatment for gout, it is no longer widely used because it can cause troublesome side effects, including:
- abdominal pain
Colchicine can be very poisonous if it is taken in too high a dose. It is very important to follow the recommended dosage schedule. For most people, this means taking two to four tablets a day.
Corticosteroids are a type of steroid. They are sometimes used to treat severe cases of gout that do not respond to the treatment above.
The relief provided by corticosteroids is often rapid, although these medicines can rarely be used in the long term. This is because long-term use can often cause the following side effects:
- weight gain
- fluid retention
- osteoporosis (thinning of the bones)
- muscle weakness
- thinning of the skin
Corticosteroids can also worsen diabetes and glaucoma (an eye disease that is caused by blocked fluid in the eye).
Do not take corticosterodis if you have:
- bone marrow disease
- impaired kidney function
- impaired liver function
- heart failure
Do not take corticosteorids if you are pregnant or breastfeeding.
There are two methods that can be used to try to prevent further attacks of gout. These are:
- using medication to reduce your uric acid levels
- making lifestyle changes to reduce your uric acid levels
If you experience two or more attacks of gout within a year, you will usually be prescribed a medication to help prevent further attacks. This will usually be a medication called allopurinol.
Allopurinol helps lower your uric acid levels by disrupting the enzyme responsible for converting purines into uric acid. However, allopurinol is not a painkiller and will have no effect during a gout attack.
If you are prescribed allopurinol, you will have to take it once a day. It usually has to be taken for two to three months before you see any effects. If you are prescribed allopurinol, you will usually have to take it indefinitely. However, you may only be able to stop taking the medicine if you have a normal serum uric acid level for many years and have no attacks of gout during this time.
When you start taking allopurinol, it can sometimes cause a gout attack. It is not well understood why this happens, but it is usually advisable to delay treatment with this medication for one to two weeks after an attack of gout has settled.
However, if you do develop a flare-up of gout while taking allopurinol, you should continue the medication while your doctor prescribes additional treatment to settle the attack.
A skin rash is the most common side effect of allopurinol, affecting around 1 in 10 people. In most cases, the skin rash is mild and soon goes away. However, in a small number of cases, a skin rash can be a sign of a more serious allergic reaction. If you develop a skin rash while taking allopurinol, stop taking the medication immediately and contact your GP as soon as possible for advice.
A small number of people also have symptoms of dizziness, loss of balance and drowsiness when they start taking allopurinol. Exercise caution when driving or operating heavy machinery until you are sure that you are not affected by these side effects.
Some foods are high in purines. Avoiding eating them can help reduce your risk of having a gout attack. You may want cut out the foods below altogether, or at least eat only a moderate amount:
- meat, particularly kidney, liver, veal, turkey and venison
- seafood, particularly anchovies, herring, mackerel, sardines, fish roe, mussels and scallops
- certain types of vegetables, such as asparagus, kidney beans, lima beans, lentils and spinach
- foods or supplements that contain yeast extract, such as Marmite and Quorn
If you are overweight, the levels of uric acid in your blood often rise. Losing weight will help reduce your uric acid levels significantly.
If you need to lose weight, it is important to follow a balanced, calorie-controlled diet. Do not crash diet. A high-protein, low-carbohydrate diet should be avoided because high-protein foods often contain high levels of purines.
Ensure that you get plenty of regular exercise. Not only will this reduce your urate levels and decrease your risk of developing gout, but it will also leave you feeling more energised and healthier.
If you have a gout attack, you need to keep the joint rested and elevated (raised). Avoid exercise that puts strain on the affected muscles or joints. Swimming is a good way to stay fit without putting pressure on your joints as the water supports your weight.
It is important to drink plenty of water. Aim to drink about 1.2 litres (six to eight glasses) a day, or more if you are exercising or when it is hot. Keeping yourself well hydrated will reduce the risk of crystals forming in your joints.
Some types of alcoholic drinks are associated with a greater risk of developing gout than others.
Beer and stout, which contain significant quantities of purines, carry a greater risk for the development of gout than equivalent units of spirits, such as vodka and whiskey.
A survey has shown that daily consumption of a small glass of wine is not associated with an increased risk of developing gout.
However, binge drinking of any kind of alcohol can bring on an attack in people who have previously suffered with gout. Men should not drink more than three to four units of alcohol a day and women no more than two to three units a day.
Other medical conditions can increase your risk of developing gout. These include:
If you have one of these conditions, it is important to manage and treat it as fully as possible. If you manage a condition, such as psoriasis, effectively, it will help prevent gout from recurring.
Complications of gout
Frequent and recurring attacks of gout may eventually damage your joints permanently. If you do not treat an attack of gout, future attacks may become more frequent and prolonged, and your likelihood of developing permanent joint damage will be increased.
Sometimes, the crystals of uric acid in your tissues can build up, causing small white lumps (tophi) to form underneath your skin.
Tophi are usually harmless and painless, but they can form in awkward places, such as at the ends of your fingers. It usually takes at least 10 years after your first attack of gout for tophi to develop. They commonly develop on the fingers, forearms, ears and toes, but can occur anywhere in the body, even in the spinal canal or vocal cords.
In rare cases, tophi can become inflamed, which can sometimes cause the surrounding bone and tissue to become damaged. If you have tophi that are large or painful, you may have difficulty doing everyday tasks, such as preparing food or dressing yourself.
Speak to your GP if you have tophi and you have difficulty performing everyday tasks. Your GP can give you advice on how to make these activities easier. If you have very large or painful tophi, they may have to be surgically removed.
Occasionally, the uric acid crystals that cause gout can collect in your urinary tract, resulting in kidney stones. Around 10-25% of people with gout develop kidney stones. Some kidney stones interfere with the flow of urine, resulting in pain when you pass urine, and can make you feel that you need to pass urine more often. Kidney stones can also cause an infection to develop in your urinary system.
Most kidney stones are small and pass out of your system naturally, usually within a day or two. Drink plenty of water as this will help flush the stones out of your system naturally.
You may be prescribed medication to make your urine less acidic, which should help dissolve any kidney stones that may have developed.
As well as affecting you physically, gout can also affect your mood and your work and home life. The severe pain that gout causes can make it difficult to get around, which can sometimes lead to feelings of depression or anxiety.
Your GP will discuss ways to make your day-to-day life easier during a gout attack. They can also help you deal with any feelings of depression that you may experience.