Introduction
Gout is a type of arthritis, in which crystals of sodium urate produced by the body can form inside 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 usually affected, but it can develop in any joint.
Symptoms can develop rapidly to their worst point in 6-24 hours and usually last for 3-10 days (this is sometimes known as a gout attack). After this time, the joint will start to feel normal again and any pain or discomfort should eventually disappear completely.
Most people with gout will have further attacks in the future.
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.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 to form in and around joints.
These hard, needle-shaped crystals build up slowly over several years. You will not know this is happening.
The crystals may cause two problems:
- Some may spill over into the soft lining of the joint (synovium), which causes the pain and inflammation associated with gout.
- Some pack together to form hard, slowly expanding lumps of crystals (tophi) which can cause progressive damage to the joint and nearby bone; this eventually leads to irreversible joint damage which causes pain and stiffness when the joint is being used.
Factors which 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
- having high blood pressure or
- 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
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.Treating gout
There are two main goals in treating gout:
- relieving symptoms during an attack of gout: using the (NSAIDs) types of painkillers; in some cases alternative medications may also be required
- preventing future gout attacks: through a combination of lifestyle changes (such as losing weight if you are overweight) and taking a medication called allopurinol to lower levels of uric acid
When medication is taken as directed with recommended lifestyle changes, such as changing your diet and drinking less alcohol, many people reduce their uric acid levels sufficiently over time and dissolve the crystals that cause gout.
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.Who is affected
Gout is more common in men than in women. This is mainly because the female hormone oestrogen that is released during the female reproductive cycle reduces a woman's levels of uric acid by increasing excretion of uric acid via the kidneys.
Gout symptoms usually occur after the age of 30 in men, and after 60 in women. After the menopause, uric acid levels rise in women and they too can become liable to getting gout. The incidence of gout increases with age; it affects 1 in 14 older men and 1 in 35 older women.
Complications
Complications of gout are uncommon but can include:
- – 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
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.Symptoms
The most common symptom of gout is sudden and severe pain in one or more joints; typically your big toe. Gout is extremely painful; some people feel it's as painful as childbirth.
Symptoms often develop at night, although they can occur at any time. Other symptoms include:
- 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 painful.
What joints are affected?
Seventy per cent of people with gout experience their first attack in the big toe, and most 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 peripheral limb joint and can occur in two or more joints at the same time.
Affected joints may include:
- midfoot
- 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 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.
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. Some only experience a few attacks in their lifetime.
When to seek medical advice
Always see your doctor if you suspect you have gout particularly if it hasn't been previously diagnosed. It is important that a diagnosis is confirmed because occasionally more serious conditions, such as an infected joint, can cause similar symptoms.
You may also require treatment with prescription medication that only your doctor (or a specialist) can provide.
When to seek immediate medical advice
Contact your doctor immediately or call if you have a high temperature of above 38C (100.4F) as well as joint pain and swelling, as you may have an infection inside the joint (septic arthritis).
Causes
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.
Uric acid
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 to form, usually in a joint 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 gout.
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 two categories:
- medical conditions known to increase levels of uric acid, such as obesity, high blood pressure (hypertension), high lipid levels and long-standing impairment of kidney function
- lifestyle factors, such as diet or certain types of medication that you may be taking
These risk factors are discussed in more detail below.
Medication
Certain types of medication can increase your uric acid levels and your risk of developing gout. These include:
- diuretics, used to treat high blood pressure (hypertension) or an abnormal build-up of fluid in your body
- niacin, used to treat high cholesterol
Gender
Men are more likely to develop gout than women 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 symptoms start later in women than in men.
Diet
Foods naturally high in purines include:
- beef
- pork
- bacon
- lamb
- seafood
- liver
- kidneys
Alcohol
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. (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.
Medical conditions
Medical conditions that can increase your risk of developing gout include:
- high blood pressure (hypertension)
- diabetes, both and
- having levels in your blood
Susceptibility
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.
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.
One theory is that certain genes you inherit from your parents may make you more likely to develop gout by causing your kidneys that are otherwise healthy to be relatively inefficient at excreting uric acid. Several genes have recently been identified that are associated with high uric acid levels and gout and which influence uric acid elimination by the kidney.
Diagnosis
The most accurate way to diagnosis gout is to check your joints for the presence of crystals. However, your doctor may only need to 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 pain and problems with the joints).
Therefore, your doctor 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.
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.
The test involves analysing a sample of blood taken from a vein in your arm to measure the amount of uric acid in your blood.
A raised uric acid level is often an indication you may have developed gout. 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.
Synovial fluid
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 is taken using a needle and syringe. It is then examined under a microscope. If you have gout, there will nearly always be crystals of sodium urate in the sample. This sort of test will also help to rule out other crystals (calcium pyrophosphate) that can cause similar attacks of inflammation, as well as an infection in the joint such as
(when a joint becomes infected with bacteria).X-ray
An
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).Confirming the diagnosis
As checking the joints for crystals is not always practical in general practice, a checklist is often used. This is based on the known pattern of symptoms associated with the condition.
The checklist used is as follows:
- You have had more than one attack with symptoms of pain, swelling and inflammation.
- You have experienced high levels of inflammation within just one day of the onset of symptoms.
- Symptoms only affect one joint at a time.
- The joint in your big toe or other foot joints have been affected.
- 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.
Follow-up appointment
About four-to-six weeks after your gout attack has subsided, your doctor may ask you to return for a follow-up appointment to check your serum uric acid level.
Your doctor can also give you an advance prescription of painkilling medication so that you can deal with attacks of gout promptly.
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.Treatment
If you are diagnosed with gout, your treatment plan will have two goals:
- relieving the symptoms of a gout attack
- preventing further attacks
Relieving symptoms
Self-care techniques
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 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 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.
Medication
(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:
- diclofenac
- indometacin
- naproxen
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) that reduces the risk of the NSAID causing indigestion,
and bleeding from the stomach.People with reduced kidney function or those with conditions such as stomach ulcers or bleeding should avoid using NSAIDs.
Colchicine
If you are unable or do not want 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.
Colchicine can be an effective treatment for gout. However, it should be used at low doses since it can cause upsets, including:
- nausea
- abdominal pain
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 that do not respond to other treatments.
A short course of steroid tablets often provides relief, but can't be used long-term as they cause side effects including:
- weight gain
- thinning of the bones ()
- bruising
- muscle weakness
- thinning of the skin
- increased vulnerability to infection
Corticosteroids can also exacerbate
and (an eye condition which can cause blindness if untreated).Corticosteroids may not be suitable for you if you have:
- bone marrow disease
- impaired kidney function
- impaired liver function
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
Usually 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
The main treatment for gout is known as urate-lowering therapy or ULT. The goal of ULT is to lower uric acid levels below the levels required for crystals to form (the saturation point).
This should also help to dissolve existing crystals leading to an effective cure for gout. But to maintain the "cure" you would need to continue with ULT on a daily basis.
Many people with gout begin ULT as soon as they are diagnosed to reduce the frequency of 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 doctor or the doctor in charge of your care. If you agree to start ULT, usually the ULT medication to try first is called allopurinol.
Allopurinol
Allopurinol helps to lower uric acid levels by inhibiting the enzyme (xanthine oxidase) responsible for converting purines into uric acid, thus reducing 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 and usually for up to a year or two before all crystals have dissolved and no further attacks can 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 rapid reduction of uric acid levels to below the saturation point causes existing crystals in 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 from a low starting dose (e.g. 100mg daily) to the recommended dose.
You may continue to have gout attacks until all the existing crystals have dissolved, which is perfectly normal.
So if this does happen, don'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 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, it’s 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 doctor for advice. It may be necessary to stop taking allopurinol and try an alternative ULT (see below).
Other side effects of allopurinol include:
- diarrhoea
If you are currently being treating 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) then you will probably not be able to take allopurinol for safety reasons.
Allopurinol may also not be suitable if you have severe kidney disease.
Patients with kidney problems may be started on a lower dose (50mg daily) and have lower monthly increases (50mg) of allopurinol.
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, thus reducing the body’s production of uric acid.
However, unlike allopurinol, it is broken down by the liver and not the kidney, so can be used in patients with kidney disease without concerns over side effects.
Also unlike allopurinol, it only comes in two doses (80mg or 120 mg daily). Because even 80 mg daily may quickly reduce uric acid levels below the saturation point, initiation of even the lowest dose of febuxostat often triggers acute attacks.
To try to reduce the frequency and severity of this side effect your doctor may prescribe you regular daily oral NSAID or colchicine (one-to-two tablets daily) for up to six months following the start of febuxostat as prophylaxis (preventative treatment).
Common side effects of febuxostat include:
- an increased number of acute gout attacks (discussed above)
- 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 doctor for advice.
Currently, febuxostat is not considered suitable for people with heart problems (especially heart failure), or with serious kidney disease.
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 only to 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 frequently or in large quantities can help reduce the risk of a gout attack:
- 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
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. 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.
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.
Complications
Tophi
Sometimes crystals of uric acid in your tissues build up causing small lumps known as tophi to form underneath your skin. They often have a white or yellow aspect to their appearance.
Tophi are usually painless, but they can form in awkward places, such as at the ends of your fingers. It usually takes several years after the first attack of gout for tophi to develop, but some people develop tophi even before experiencing an acute attack.
They usually form on toes, heel, knees, fingers, forearms and elbows, but can occur anywhere in the body, even in the spinal canal or vocal cords though this is rare.
If there are tophi below the skin then there will be more within the cartilage and bone of your joints.
They are usually taken as a sign of severe gout and a reason to start uric acid lowering therapy, such as the medication allopurinol (read more about the
).Successful lowering of the uric acid to below the saturation point for urate crystal formation will prevent the tophi from getting any bigger, and allow them to slowly reduce in size as the crystals dissolve.
Occasionally tophi can become inflamed, and even produce a discharge consisting of a mixture of pus and white toothpaste-like material. 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 doctor if you have tophi and difficulty performing everyday tasks. Your doctor can give advice on how to make these activities easier. If you have very large or painful tophi, they may have to be surgically removed.
Joint damage
Continuing deposition of urate crystals, especially as the hard lumps (tophi) and damage they cause may eventually damage your joints permanently.
If you don't treat gout by reducing uric acid levels to below saturation point, future attacks may become more frequent and prolonged, and your likelihood of developing permanent joint damage will be increased.
In the most serious cases surgery may be required to repair or replace a damaged joint.
Kidney stones
Occasionally, high levels of uric acid can lead to formation of uric acid crystals in your urinary tract, resulting in
. 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 you need to pass urine more often.Kidney stones can also cause an infection in your urinary system.
Most kidney stones are small and pass through your system naturally, usually within a day or two. Drink plenty of water as this will help flush the stones naturally.
You may be prescribed medication to make your urine less acidic, which should help dissolve any kidney stones that may have developed.
Psychological effects
As well as affecting you physically, gout can also affect your mood, work and home life. The severe pain that gout causes can make it difficult to get around, which can sometimes lead to feelings of
or .Your doctor 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 you may experience.