Originally posted on Medical News Today by James McIntosh
What is gout?2-4
Gout is a common form of inflammatory arthritis – a condition affecting the joints and musculoskeletal system. It is the most common form of inflammatory arthritis in men, and although it is more likely to affect men, women become more susceptible to it after the menopause.
Gout commonly affects the base of the big toe. When affecting this area, the condition can also be referred to as podagra.
The condition is characterized by sudden and severe pains, redness and tenderness in the joints, most commonly in the base of the big toe. When affecting the big toe, gout can also be referred to as podagra.
These symptoms occur when uric acid, a bodily waste produce, is deposited in the form of needle-like crystals in tissues and fluids within the body. Chalky deposits of uric acid known as tophi can also form as lumps under the skin surrounding the joints. Uric acid crystals can also collect in the kidneys, sometimes resulting in kidney stones.
At its most disabling, gout can cause permanent damage to joints and the kidneys. It normally takes a long period, around 10 years, without any proper treatment for the disease to reach this advanced stage, however.
The Centers for Disease Control and Prevention (CDC) report that 2.6 million Americans were affected by gout in 2005 and that this figure is projected to rise to 3.6 million by 2025.1
What causes gout?3-7
Gout is caused initially by an excess of uric acid in the blood (hyperuricemia). Uric acid is produced in the body through the breakdown of purines – specific chemical compounds that are found in certain foods such as meat, poultry and seafood.
Normally, uric acid dissolves in the blood and is excreted from the body in urine via the kidneys. If too much uric acid is produced or not enough is excreted then it can build up and form the needle-like crystals that cause inflammation and pain in the joints and surrounding tissue.
There are a number of factors that can increase the likelihood of hyperuricemia, and therefore gout:
- Age and gender: men produce more uric acid than women, though women’s levels of uric acid approach those of men after the menopause
- Genetics: a family history of gout increases the likelihood of the condition developing
- Lifestyle choices: alcohol consumption interferes with the removal of uric acid from the body. Eating a high-purine diet also increases the amount of uric acid in the body
- Lead exposure: chronic lead exposure has been linked in some cases to gout
- Medications: certain medications can increase the levels of uric acid in the body, such as diuretics and drugs containing salicylate
- Weight: being overweight increases the risk as there is more tissue in the body for turnover or breakdown, leading to the production of excess uric acid
- Other health problems: if the kidneys are unable to eliminate waste products adequately (renal insufficiency) then uric acid levels can remain high. Other conditions that can contribute are high blood pressure (hypertension), diabetes and hypothyroidism.
Signs and symptoms1,3,4,8
Gout usually becomes symptomatic suddenly without warning, often in the middle of the night. The main symptoms are intense joint pain that subsides to discomfort, inflammation and redness. Gout frequently affects the large joint of the big toe, but can also commonly affect the ankles, knees, elbows, wrists and fingers.
There are four stages through which gout progresses. Each is characterized by its symptoms (or lack of).
Gout patients often suffer from acute inflammation around their joints.
It is possible for a person to have hyperuricemia without any outward symptoms. At this stage, treatment is not required, though urate crystals are being deposited in tissue and causing slight damage.
This stage occurs when the urate crystals that have been deposited suddenly cause acute inflammation and intense pain. This sudden attack is referred to as a “flare” and will normally subside within 3-10 days. Flares can sometimes be triggered by stressful events, alcohol and drugs.
Interval or inter critical gout
This stage is the period in between attacks of acute gout. Subsequent flares may not occur for months or years, though if not treated over time they can last longer and occur more frequently. During this time, further urate crystals are being deposited in tissue.
Chronic tophaceous gout
This final stage is the most debilitating form of the disease. Permanent damage may have been dealt to joints and the kidneys. The patient can suffer from chronic arthritis and develop tophi – big lumps of urate crystals – in cooler areas of the body such as the joints of the fingers.
It takes a long time without treatment to reach the stage of chronic tophaceous gout, around 10 years. It is very unlikely that a patient receiving proper treatment would progress to this stage.
Tests and diagnosis3,4,9
Gout can be tricky to diagnose as its symptoms, when they do manifest, are similar to those of other conditions. While hyperuricemia occurs in the majority of people that develop gout, it may not be present during a flare. On top of that, the majority of people with hyperuricemia do not develop gout.
One diagnostic test that doctors can carry out is the joint fluid test, where fluid is extracted from the affected joint with a needle. The fluid is then examined to see if any urate crystals are present.
As joint infections can also cause similar symptoms to gout, a doctor can look for bacteria when carrying out a joint fluid test in order to rule this condition out as well.
Doctors can also conduct a blood test to measure the levels of uric acid in the blood, but as specified, people with high uric acid levels do not always experience gout. Equally, some people can develop the symptoms of gout without having increased levels of uric acid in the blood.
Finally, doctors can search for urate crystals around joints or within a tophus.
One condition that can often be confused with gout is pseudogout. The symptoms of pseudogout are very similar to those of gout, the difference being that the joints are irritated by calcium phosphate crystals rather than urate crystals. This means that pseudogout requires different treatment to gout.
Treatment and prevention3,4,9,10
The majority of gout cases are treated with medication. Medication can be used to treat the symptoms of gout attacks, prevent future flares and reduce the risk of gout complications such as kidney stones and the development of tophi.
Commonly used medications are nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine or corticosteroids. These reduce inflammation and pain in the areas affected by gout and are commonly administered orally.
It is recommended that you drink between 2 and 4 liters of water a day to reduce the risk of gout.
Medications can also be used to either reduce the production of uric acid (xanthine oxidase inhibitors such as allopurinol) or improve the kidney’s ability to remove uric acid from the body (probenecid).
There are many lifestyle and dietary guidelines that can be followed to protect against future flares or prevent gout from occurring in the first instance:
- Maintain a high fluid intake (2-4 liters a day)
- Avoid alcohol
- Maintain a healthy body weight
- Eat a balanced diet
- Limit fish, meat and poultry intake.
If attempting to lose weight, avoid low-carbohydrate diets. If carbohydrate intake is insufficient, the body is unable to burn its own fat properly, releasing substances called ketones into the bloodstream. This results in a condition called ketosis that can increase the level of uric acid in the blood.
It is most important to avoid foods that are high in purines, to ensure that the levels of uric acid in the blood do not get too high. Here is a list of high-purine foods to be wary of:
- Beef kidneys
- Dried beans and peas
- Game meats
Uric acid’s role in gout has been clearly defined and understood. As a result of this and the wide availability of relevant medications, gout is a very controllable form of arthritis.