What is gout?
Gout is an inflammatory condition affecting one or more joints. Many people think that gout occurs when people drink too much alcohol and eat rich foods. However, while these actions can affect gout, they are not the main cause. There are two types of gout: primary and secondary. Primary gout is the most common form and most people with this form have a family history of the disease. Primary gout usually first appears between the ages of 30 and 60 years and predominantly affects men. Secondary gout usually occurs as a result of long-term treatment with diuretics (water tablets). This form is usually found in those older than 65 years and affects both men and women. It is often associated with osteoarthritis.
What are the symptoms of gout?
Gout usually affects a single joint but may affect several. The joints of the foot, in particular the big toe, are most susceptible to gout. Other joints commonly affected include the ankles, knees, wrists, and elbows. An episode of gout often starts early in the morning with localized aching and irritation. The affected joint quickly becomes very painful and so tender that even a light touch is painful. The joint and surrounding tissues swell and the skin around the joint becomes red and shiny. If left untreated, a gouty attack will usually resolve on its own in about 5 to 15 days. Some people never have more than one gouty attack, while others may not have a second attack for years. However, in most people a second attack occurs within a year of the first. After this, the attacks gradually become more frequent and the number of joints affected gradually increases. Repeated attacks of gout may cause irreversible changes leading to loss of function and deformity of the joint(s).
What causes gout?
Nearly all people with gout have hyperuricemia, a condition in which there is too much uric acid in the blood. However, many people with hyperuricemia never develop gout. Hyperuricemia is an inherited condition, but environmental factors can also play a part, for example, treatment with diuretics (water tablets). Diuretics are used to lower high blood pressure by getting rid of excess water in the body. These medicines can interfere with the ability of the kidneys to remove uric acid from the blood, resulting in elevated uric acid levels. If uric acid levels remain high, uric acid crystals can develop. These crystals can be deposited in the affected joint, causing nodules or lumps just under the skin; these nodules are known as tophi.
There are several other factors besides diuretic treatment that may cause increased uric acid levels. For example, not drinking enough fluids means that the urine will be unable to dissolve all the uric acid, resulting in increased amounts in the blood. Dietary factors and excessive alcohol intake can also affect the body’s ability to deal with uric acid. An episode of gout may be triggered by several different factors including an excess of alcohol, overeating rich foods, crash dieting, injury to a joint or surgery.
What tests confirm a diagnosis of gout?
A blood test can measure the amount of uric acid in the blood. A high level does not necessarily indicate gout and a normal level does not mean that gout is not present. It does, however, give a good indication. Fluid may be extracted from an affected joint in order to look for uric acid crystals. If it is thought that diet may be a contributing factor, then urine samples can be collected to see how much uric acid the body is producing. The symptoms of osteoarthritis can be similar to those of gout and the two conditions often affect the same joints. Tests will usually be performed to determine the actual cause of the condition. It is possible for uric acid crystals to be deposited in a joint that is already affected by osteoarthritis. If this happens it may be difficult to diagnose gout.