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Overview of gout

Mō te porohau

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Gout is a form of arthritis caused by uric acid. It causes severe pain, swelling and redness in one or more of your joints.

Gout can come on suddenly and often starts at night. It often affects your big toe but can affect your knee, foot, wrist, ankle, hand and elbow joints.

Uric acid is a chemical mainly made in your body but some comes from purines in food. Your kidneys usually filter out the extra uric acid which then comes out in your wee (urine).

If you don't get rid of enough uric acid, the levels in your blood increase, causing gout. The high levels of uric acid in your blood can turn into tiny, sharp, glass-like crystals which collect in your joints. The crystals can also cause lumps under your skin called tophi.

If not treated, gout can damage your joints and kidneys.

Risk factors for gout

Genetics. The main risk is from the genetic factors (passed on from your parents) which you are born with. This is particularly common in Māori and Pacific people. You can’t change these but you can reduce other risk factors
Increasing age. Most gout happens after the age of 40
What you eat and drink. Having a lot of sugary drinks and alcohol or eating a lot of food high in purine, such as meat and seafood, make you more likely to get gout
Being an unhealthy weight
Having high blood pressure (hypertension)
Some tablets such as diuretics used for high blood pressure and heart failure
Other medical conditions such as kidney disease.

Diagnosing gout

Your GP will ask you about your symptoms and examine the affected parts of your body. They can usually diagnose gout by examining your sore joint. They will arrange a blood test to measure your uric acid levels, either at the time of your attack, or later.

If it's not clear whether you have gout or a joint infection, you may need to have a procedure called a joint aspiration. This involves taking fluid out of the affected joint using a needle and syringe. The fluid is sent to a laboratory to be tested.