Gout
Introduction
Gout
Gout is a type of arthritis where crystals of sodium urate form inside and around joints.
The most common symptom is sudden and severe pain in the joint, along with swelling and redness. The joint of the big toe is commonly affected, but it can develop in any joint.
Symptoms develop rapidly and are at their worst point in just 6 to 24 hours. Symptoms usually last for 3 to 10 days (this is sometimes known as a gout attack).
After this time, the joint will start to feel and look normal again, and the pain of the attack should disappear completely.
Almost everyone with gout will have further attacks in the future.
What causes gout?
Gout is caused by a build-up of uric acid in the blood. Uric acid is a waste product made in the body every day and excreted mainly via the kidneys. It forms when the body breaks down chemicals in the cells known as purines.
If you produce too much uric acid or excrete too little when you urinate, the uric acid builds up and may cause tiny crystals of sodium urate to form in and around joints.
These hard, needle-shaped crystals build up slowly over several years. You will not know this is happening.
Eventually, when there is a high concentration of crystals in your joints, the crystals may cause two problems:
some may spill over from the joint cartilage and inflame the soft lining of the joint (synovium), causing the pain and inflammation of an acute attack of gout
some pack together to form hard, slowly expanding lumps of crystals (tophi), which can cause progressive damage to the joint cartilage and nearby bone; this eventually leads to irreversible joint damage, which causes pain and stiffness when the joint is being used
Factors that increase your risk of gout include:
age and gender – gout is more common when you get older and is three to four times more likely in men
being overweight or obese
having high blood pressure or diabetes
having close relatives with gout (gout often runs in families)
having long-term kidney problems that reduce the elimination of uric acid
a diet rich in purines, such as frequently eating sardines and liver
drinking too much beer or spirits – these types of alcoholic drinks contain relatively high levels of purines
Treating gout
There are two main goals in treating gout:
relieving symptoms – this can be done by using ice packs and taking non-steroidal anti-inflammatory drug (NSAID) painkillers; in some cases, alternative medications such as colchicine or corticosteroids may also be needed
preventing future gout attacks – through a combination of lifestyle changes, such as losing weight if you are overweight, and taking a medication such as allopurinol, which lowers uric acid levels
It is important to take any prescribed medication as directed and make any recommended lifestyle changes, such as losing weight.
Many people are able to reduce their uric acid levels sufficiently to dissolve the crystals that cause gout, resulting in their gout being "cured" with no further attacks.
Who is affected?
Gout is more common in men than in women. This is mainly because the female hormone oestrogen, which is released during the female reproductive cycle, reduces a woman's levels of uric acid by increasing the excretion of uric acid via the kidneys.
After the menopause, uric acid levels rise in women and they too can become liable to getting gout.
It is estimated that, overall, 1 in 45 people in the UK have gout. However, gout is more common in older adults, affecting 1 in 7 older men and 1 in 16 older women. This makes it the most common type of arthritis after osteoarthritis.
Gout symptoms usually occur after the age of 30 in men and after 60 in women.
Complications
Complications of gout are uncommon but can include:
kidney stones – high levels of uric acid can also lead to stones (uric acid and calcium stones) developing inside the kidneys
tophus formation – tophi are small to large firm lumps sometimes visible and easily felt under the skin
permanent joint damage – caused by ongoing joint inflammation between the acute attacks, and by formation of tophi within the joint that damage cartilage and bone; this is usually only a risk if gout is left untreated for many years
Symptoms of gout
The most common symptom of gout is sudden and severe pain in one or more joints, typically your big toe. Gout is extremely painful.
Symptoms often develop at night, although they can occur at any time. Other symptoms include:
your joint being very tender, to the point of being unable to bear anything touching it
swelling (inflammation) in and around the affected joint
red, shiny skin over the affected joint
peeling, itchy and flaky skin over the affected joint as the inflammation subsides
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 unbearable.
Which joints are affected?
Seventy per cent of people with gout experience their first attack in the big toe and most people with gout experience pain in their big toe at some point.
However, gout can affect almost any joint and can occur in more than one joint at the same time. The joints towards the ends of the limbs tend to be affected more often and may include:
the midfoot (the area where your shoelaces would sit)
ankles
knees
fingers
wrists
elbows
If gout is left untreated, it is more likely to affect more than one joint as it progresses.
Pattern of symptoms
It is difficult to predict when an attack will occur. Symptoms typically develop rapidly over just a few hours and usually last for 3 to 10 days. After this time, the joint will start to feel normal again and any pain or discomfort associated with the attack should eventually disappear completely.
Just over half of all people with gout (62%) experience a repeat attack within a year. You may experience symptoms every few weeks, months or years, but it is impossible to predict when the condition will recur.
Although some people may experience just a few attacks in their lifetime, the vast majority of people with gout experience attacks that increase in frequency over time. New joints will often start to be affected.
When to seek medical advice
Always see your GP if you suspect you have gout, particularly if it hasn't been previously diagnosed.
It is important that a diagnosis is confirmed because more serious conditions, such as an infected joint, can sometimes cause similar symptoms.
You may also require treatment with prescription medication that only your GP (or a specialist) can provide.
When to seek immediate medical advice
Contact your GP immediately or call 111 if you have both:
a high temperature of above 38ºC (100.4ºF)
joint pain and swelling that is still getting worse after the first 24 hours
Causes of gout
Gout is caused by a build-up of uric acid in the blood. Uric acid is a waste product that forms when the body breaks down chemicals in the cells known as purines.
Most uric acid is removed from the body through the kidneys. A small amount is removed through the digestive system.
Sodium urate crystals
Uric acid usually remains dissolved in your blood and passes through your kidneys into your urine so it can be passed out of your body.
If you produce too much uric acid or excrete too little when you urinate, the uric acid will build up and may cause microscopic crystals of sodium urate to form, usually in joints or surrounding tissue.
The crystals may spill over from the joint cartilage into the joint space, where they trigger a reaction from the soft lining (synovium), which produces the intense pain and inflammation associated with a gout attack.
Gout attacks occur most frequently in the joints of the feet and hands, possibly because the temperature in these joints is often lower than the rest of the body, which increases the likelihood of crystals forming. The knees and elbows are the next most commonly affected. Joints close to the body, such as shoulders, hips, the neck or back are very rarely affected.
Risk factors
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 three categories:
medical conditions known to increase levels of uric acid
lifestyle factors – such as diet or certain types of medication
genetics – certain genes you inherit from your parents may make you more likely to develop gout
These risk factors are discussed in more detail below.
Medical conditions
Medical conditions that can increase your risk of developing gout include:
high blood pressure (hypertension)
diabetes – both type 1 diabetes and type 2 diabetes
kidney disease
having high levels of fat and cholesterol levels in your blood
having osteoarthritis in your feet, knees or hands
Medication
Certain types of medication can increase your uric acid levels and your risk of developing gout. These include:
diuretics (water tablets), which are used to treat high blood pressure or an abnormal build-up of fluid in your body
other drugs used to treat high blood pressure, such as beta-blockers, ACE inhibitors and calcium channel blockers
low-dose aspirin
niacin, which is used to treat high cholesterol
Gender
Men are more likely to develop gout than women because their uric acid levels rise during puberty and remain higher than women through adulthood.
During the menopause, women experience a similar, albeit smaller, rise in their uric acid levels. This explains why symptoms usually start later in women than in men.
Diet
Foods naturally high in purines include:
red meat – such as beef, lamb and pork
seafood – especially shellfish and oily fish
offal – such as liver, kidneys and heart
Alcohol
Alcoholic drinks raise the level of uric acid in the blood by increasing its production in the liver and reducing how much is passed out in urine.
Beer and spirits do this more than wine, and beer also contains significant quantities of purines. Moderate consumption of wine – one or two glasses a day – should not significantly increase your risk of gout.
Sugary drinks
Research has shown a possible link between gout and certain sugary drinks.
Specifically, a study found that men who regularly drank sugar-sweetened soft drinks and drinks with high levels of fructose (a naturally occurring sugar found in many fruits) had an increased risk of gout.
Diet soft drinks were not found to increase the risk of gout.
Family history
Studies have shown that gout often runs in families. Around one in five people with gout have a close family member who also has the condition.
Susceptibility
It is still uncertain 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.
Diagnosing gout
The most accurate way to diagnose gout is for your doctor to check your joints for the presence of crystals. However, this test is often not practical to carry out at your local GP practice.
Instead, your GP will first ask about your symptoms and medical history to make a diagnosis.
They will usually ask the following questions:
Which joints are affected?
How quickly did the symptoms appear?
How often do you have symptoms?
Are you taking any medication?
Does anyone in your family have gout?
They will also ask you about your diet, particularly your intake of beer, spirits and foods high in purines, such as red meat and seafood.
Further tests
Many conditions can cause joint pain, inflammation and swelling. Gout is just one of the more than 200 different forms of arthritis (any condition that causes pain and problems with the joints).
Your GP may be unable to make a firm diagnosis straight away and you may be referred for further tests. These will either confirm the diagnosis of gout or rule out other conditions.
Joint fluid
A sample of fluid (synovial fluid) may be taken from the affected joint. This test helps to rule out other crystals (calcium pyrophosphate) that can cause similar attacks of inflammation, as well as an infection in the joint (septic arthritis).
The fluid sample is taken using a needle and examined under a microscope. If you have gout, there will nearly always be crystals of sodium urate in the sample.
Blood test
A type of blood test known as a serum uric acid test may be used to measure the amount of uric acid in your blood.
This test is 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.
However, a serum uric acid test is not definitive. Some healthy people without gout have high uric acid levels in their blood, while others who experience an attack of gout have a normal level.
X-ray
An X-ray is rarely used to diagnose gout because inflammation caused by gout 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).
Ultrasound scan
An ultrasound scan of an affected joint is a simple and safe investigation that is increasingly used to detect urate crystals within the joint cartilage.
It can also detect urate crystals deep in the skin that are not obvious during a physical examination.
Follow-up appointment
About four to six weeks after your gout attack has subsided, your GP may ask you to return for a follow-up appointment to check your serum uric acid level.
Your GP can also give you an advance prescription of painkilling medication so that you can deal with attacks of gout promptly.
Treating gout
If you are diagnosed with gout, your treatment plan will first aim to relieve the symptoms of an attack. Further treatment aims toprevent attacks by lowering uric acid levels.
Relieving symptoms
Self-care techniques
During a gout attack, it is important to rest, raise your limb and avoid knocking or damaging the affected joint.
Keeping the affected joint cool should also help. Remove surrounding clothing and apply an ice pack to it, such as a bag of frozen peas or some ice wrapped inside a towel.
Apply the ice pack to your joint for around 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.
Medication
Non-steroidal anti-inflammatory drugs (NSAIDs) are a type of painkiller usually recommended as an initial treatment for gout. They work by reducing the levels of pain and inflammation.
NSAIDs often used to treat gout include:
naproxen
diclofenac
etoricoxib
If you have been prescribed NSAIDs for gout, it is best to keep them near you at all times so 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 should be prescribed together with a medication called a proton pump inhibitor (PPI), which reduces the risk of the NSAID causing indigestion, stomach ulcers and bleeding from the stomach.
People who have reduced kidney function, conditions such as stomach ulcers or bleeding, or who are using certain medications such as warfarin or treatments for blood pressure should avoid using NSAIDs.
Colchicine
If you are unable to take NSAIDs or if NSAIDs are ineffective, colchicine can be used instead.
Colchicine is derived from the Autumn crocus plant. It is not a painkiller, but works by reducing the ability of the urate crystals to inflame the joint lining (synovium), which reduces some of the inflammation and pain associated with a gout attack.
It is best to keep them near you at all times so you can use them at the first sign of a gout attack.
Colchicine can be an effective treatment for gout. However, it should be used at low doses as it can cause side effects, including:
nausea
abdominal pain
diarrhoea
Colchicine can cause major gut problems if taken in too high a dose. It is important to follow the recommended dose. For most people, this means taking no more than two to four tablets a day.
Corticosteroids
Corticosteroids are a type of steroid sometimes used to treat severe cases of gout in people that:
do not respond to other treatment
are unable to take or cannot tolerate an NSAID or colchicine
A short course of steroid tablets often provides relief, but can't be used long-term in high doses as they cause side effects, including:
weight gain
thinning of the bones (osteoporosis)
bruising
muscle weakness
thinning of the skin
increased vulnerability to infection
Corticosteroids can also exacerbate diabetes and glaucoma (an eye condition that can cause blindness if left untreated).
Corticosteroids may not be suitable for you if you have:
impaired kidney function
impaired liver function
heart failure
Corticosteroids can also be given by injection, either into muscle or directly into the affected joint, which can provide rapid pain relief.
Preventing attacks
Two methods used to try to prevent further attacks of gout are:
medication to reduce uric acid levels
making lifestyle changes to reduce uric acid levels
Medication
Drug treatment is recommended on a long-term basis for:
frequent attacks of gout and signs of tophi under the skin (tophi are small white lumps that can form under the skin)
evidence of joint damage – either in terms of associated symptoms or damage detected by X-ray
a history of kidney stones
reduced kidney function
Around 40% of people meet these criteria when gout is first diagnosed. More than 80% of people develop these symptoms within five years. Drug treatment is therefore considered and explained to most people before their gout becomes more severe.
The main treatment for gout is known as urate-lowering therapy (ULT). The goal of ULT is to lower uric acid levels below the levels required for crystals to form (the saturation point).
This prevents any new crystals forming and also helps to dissolve existing crystals. This eventually leads to the removal of all the crystals in your body and prevents any further attacks or joint damage. But you normally need to continue with ULT on a daily basis for the rest of your life to maintain this "cure".
Many people with gout begin ULT as soon as they are diagnosed to reduce the frequency of future attacks and the risk of developing joint damage. This has to be balanced against possible side effects that can occur with ULT, although these are rare.
Discuss the potential benefits and disadvantages of ULT with your GP or the doctor in charge of your care. If you agree to start ULT, allopurinol is usually the medication that is tried first.
Allopurinol
Allopurinol helps to lower uric acid levels by inhibiting the enzyme (xanthine oxidase) responsible for converting purines into uric acid, which reduces the production of uric acid. However, allopurinol is not a painkiller and will have no effect during an attack of gout.
Allopurinol is a tablet taken once a day. The dose needs to be adjusted to ensure that the target level of serum uric acid is achieved. The aim is to maintain the level well below 360 umol/L or 6mg/dl.
The dose is usually increased every three to four weeks, depending on the results of the blood tests for uric acid.
Once this target is achieved, it often takes up to a year or two before all crystals have dissolved and no further attacks occur. The medication will then usually be taken for the rest of your life.
It can take a while to assess the most effective dose for your circumstances. You may need to have several blood tests to find the most effective dose.
When you first start taking allopurinol, it can sometimes cause a gout attack, because the rapid reduction of uric acid levels to below the saturation point causes existing crystals in the joint cartilage to partially dissolve and become smaller.
The smaller crystals can escape more easily or "shed" from the cartilage into the joint cavity, and then inflame the joint lining (synovium).
The risk of this happening is reduced by slowly increasing the dose of allopurinol as described above.
You may continue to have gout attacks until all the existing crystals have dissolved, which is perfectly normal.
If this does happen, you shouldn't lose confidence in the effectiveness of ULT. It's important to persevere with treatment to achieve the maximum benefit.
If you do develop a flare-up of gout while taking allopurinol, continue taking the medication while your doctor prescribes additional treatment to settle the attack.
Although allopurinol is taken without any side effects in most patients, around 10% do experience problems. A skin rash is the most common side effect. In most cases, this is mild and soon goes away.
However, in a small number of cases, it can be a sign of an allergic reaction. If you develop a skin rash while taking allopurinol, stop taking the medication immediately and contact your GP for advice. It may be necessary to stop taking allopurinol and try an alternative ULT.
Other possible side effects of allopurinol include:
indigestion
headache
diarrhoea
You will probably not be able to take allopurinol for safety reasons if you are currently being treated with immunosuppressant medications (often used to prevent your body rejecting a donated organ) or a type of medication called cyclophosphamide (used in the treatment of some cancers).
Patients with kidney problems may be started on a lower dose (50mg daily) and have lower monthly increases (50mg) of allopurinol.
Allopurinol may also not be suitable if you have severe kidney disease. Those with severe kidney disease may not even be started on allopurinol, but prescribed an alternative ULT such as febuxostat.
Febuxostat
Febuxostat acts in the same way as allopurinol by inhibiting the enzyme (xanthine oxidase) that produces uric acid and reducing the body's production of uric acid.
However, unlike allopurinol, it is mainly broken down by the liver rather than the kidney, which is why it can be used more easily in patients with kidney disease.
Febuxostat may be very effective at lowering the serum uric acid level. As with allopurinol, febuxostat may cause temporary worsening of your symptoms when you first start taking it.
To try to reduce the frequency and severity of this side effect, your doctor may prescribe you regular daily oral NSAIDs or colchicine (one to two tablets daily) for up to six months following the start of febuxostat as preventative treatment (prophylaxis).
Common side effects of febuxostat include:
an increased number of acute gout attacks
diarrhoea
headache
feeling sick
skin rash
If you experience more serious symptoms, such as breathing difficulties or facial swelling, stop taking febuxostat and contact your GP for advice.
Currently, febuxostat is not considered to be suitable for people with heart problems, especially heart failure.
Less commonly used ULT medications
Less commonly used ULT medications include:
benzbromarone
sulphinpyrazone
probenecid
They work by helping the kidneys to remove uric acid from the body.
Sulphinpyrazone and probenecid are now rarely used as they are not as effective as other types of ULT medications and are not suitable for people with kidney disease.
Benzbromarone is more effective in removing uric acid and can be used in people with kidney disease.
These types of medication tend to only be used if people are unable to take allopurinol or febuxostat. They need to be prescribed under the supervision of a specialist.
Lifestyle changes
Food
Some foods are high in purines. Avoiding eating the foods below can help reduce the risk of a gout attack:
offal – liver and kidneys, heart and sweetbreads
game – rabbit, pheasant and venison
oily fish – anchovies, herring, mackerel, sardines, sprats, whitebait and trout
seafood – mussels, crab, shrimp and other shellfish, fish roe and caviar
foods or supplements that contain yeast or meat extract – Marmite, Bovril, commercial gravy and beer
For more detailed information on foods to eat in moderation and low purine foods, see the following factsheet on gout and diet (PDF, 711kb)produced by the UK Gout Society.
Weight
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 you get plenty of regular exercise. Not only will this reduce your urate levels and decrease your risk of developing gout, it will also make you feel more energised and healthier.
If you have a gout attack, 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.
Water
It is important to drink plenty of water to avoid dehydration. 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.
Alcohol
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.
Studies have shown that, as long as you stick to the maximum recommended levels of alcohol intake, 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.