What is gout?
Gout causes attacks of painful inflammation in one or more joints. It is a type of arthritis .The pain of a gout attack can be severe.
What causes it?
Gout is caused by a chemical in the blood called uric acid (urate). Uric acid is usually harmless and is made in the body. Most is passed out with the urine and some from the gut with the stools (faeces). In people with gout the amount of uric acid in the blood builds up. From time to time the level may become too high and tiny grit-like crystals of uric acid may form. The crystals typically collect in a joint. The crystals irritate the tissues in the joint to cause inflammation, swelling and pain – a gout attack.
Why does uric acid build up?
Normally, there is a fine balance between the amount of uric acid (urate) that you make and the amount that you pass out in the urine and faeces. This keeps the level of uric acid in the blood in check. However, in most people with gout, their kidneys do not pass out enough uric acid and the blood level may rise. They are said to be under-excreters of uric acid. Their kidneys usually work otherwise normally.
In some people, the build-up of uric acid may due to other factors. For example:
- Drinking too much alcohol can cause uric acid to build up.
- If you do not have enough vitamin C in your diet.
- If you drink sugar-sweetened soft drinks high in fructose it can cause uric acid to build up. A recent research study found that having two drinks a day of a sugar-sweetened soft drink increased the risk of developing gout by 85%. (Drinks labelled as ‘diet’ or drinks containing artificial sweeteners were not found to increase the risk.) Fructose-rich fruits and fruit juices may also increase the risk.
- Certain foods may ‘tip the balance’ to raise your uric acid higher than normal. In particular, eating a lot of heart, herring, sardines, yeast extracts, or mussels may increase the level of uric acid. However, eating a normal balanced diet should not have much effect on the uric acid level.
- Some medicines may raise the level of uric acid. For example, ‘water’ tablets (diuretics) such as bendroflumethiazide, aspirin (at full painkiller dose – not low-dose aspirin used to prevent blood clots), and some chemotherapy medicines.
- More uric acid is made than usual in illnesses where the cells of the body have a rapid turnover. For example, severe psoriasis and some blood disorders.
- People with certain other conditions have an increased risk of developing gout.These include:
- High blood pressure.
- Kidney damage.
- Diabetes mellitus.
- Bone marrow disorders.
- Lipid disorders (especially hypertriglyceridaemia).
- Vascular disease.
- How common is gout and who gets it?
Gout affects about 1 in 200 adults. Men are more commonly affected than women. A first attack of gout typically develops in middle age but it sometimes occurs in younger people. It tends to run in some families, as there is a family history of gout in about 1 in 5 cases. It may be that the genetic make-up that you inherit from your family may be a factor in becoming an under-excreter of uric acid (urate).
What are the symptoms of gout?
Gout usually occurs in attacks. An attack typically develops quickly over a few hours. It usually causes severe pain in one joint. The base of the big toe is the most commonly affected joint. Walking can be very painful and even the weight of bedclothes can hurt.
However, any joint can be affected. Sometimes two or more joints are affected. Affected joints usually swell and the nearby skin may look red and inflamed. If left untreated, a gout attack may last several days but usually goes completely within 7-10 days. Less severe attacks can occur which may be mistaken at first for other forms of arthritis. Weeks, months or even years may go by between attacks. Some people only ever have one attack.
Is gout serious?
A gout attack can be very painful. However, other effects from gout are uncommon. Joint damage may occur if you have recurring attacks. In a few people, uric acid crystals form kidney stones or may cause some kidney damage. Sometimes the crystals form bumps (tophi) under the skin. These are usually harmless and painless but sometimes form in awkward places such as at the end of fingers. Tophi occasionally become infected.
How is gout diagnosed?
Gout is usually diagnosed if you have the typical gout symptoms and a raised blood level of uric acid. If there is doubt as to the cause of the pain and swelling, your doctor may take some fluid out of a swollen joint. This is done with a needle and syringe. The fluid is looked at under the microscope. Crystals of uric acid (urate) can be seen in the fluid to confirm the diagnosis of gout.
What is the treatment for a gout attack?
If you are able to, raise the affected limb (usually a leg) to help reduce the swelling. The easiest way to raise your leg is to recline on a sofa with your leg up on a cushion. An ice pack (or pack of frozen peas) held against the inflamed joint may ease the pain until the gout treatment medicines (below) start to work:
- Wrap the ice pack (or peas) in a towel to avoid direct skin contact and ice burn.
- Apply for about 20 minutes, and then stop. (It should not be applied for long periods.)
- Repeat as often as required BUT make sure the temperature of the affected part has returned to normal before applying again.
A short course of an anti-inflammatory will quickly ease most gout attacks (within 12-24 hours). There are several types and brands, such as Diclofenac, Indomethacin and Naproxyn.
Colchicine is an alternative medicine that eases gout attacks. It is usually only used if you have problems or side-effects with anti-inflammatory painkillers. Steroid tablets or injections can also reduce the pain and inflammation. They are another alternative if there are problems or side-effects with anti-inflammatory painkillers and colchicine.
Canakinumab is another option that has recently been introduced.