What Is Gout?
Gout is a painful condition that occurs when the bodily waste product uric acid is deposited as needle-like crystals in the joints and/or soft tissues. In the joints, these uric acid crystals cause inflammatory arthritis, which in turn leads to intermittent swelling, redness, heat, pain, and stiffness in the joints.
In many people, gout initially affects the joints of the big toe. But many other joints and areas around the joints can be affected in addition to or instead of the big toe. These include the insteps, ankles, heels, knees, wrists, fingers, and elbows. Chalky deposits of uric acid, also known as tophi, can appear as lumps under the skin that surrounds the joints and covers the rim of the ear. Uric acid crystals can also collect in the kidneys and cause kidney stones.
What Is Uric Acid?
Uric acid is a substance that results from the breakdown of purines. A normal part of all human tissue, purines are found in many foods. Normally, uric acid is dissolved in the blood and passed through the kidneys into the urine, where it is eliminated.
If there is an increase in the production of uric acid or if the kidneys do not eliminate enough uric acid from the body, levels of it build up in the blood (a condition called hyperuricemia). Hyperuricemia also may result when a person eats too many high-purine foods, such as liver, dried beans and peas, anchovies, and gravies. Hyperuricemia is not a disease, and by itself it is not dangerous. However, if excess uric acid crystals form as a result of hyperuricemia, gout can develop. The crystals form and accumulate in the joint, causing inflammation.
What Are the Four Stages of Gout?
Gout can progress through four stages:
- Asymptomatic (without symptoms) hyperuricemia. In this stage, a person has elevated levels of uric acid in the blood (hyperuricemia), but no other symptoms. Treatment is usually not required.
- Acute gout or acute gouty arthritis. In this stage, hyperuricemia has caused the deposit of uric acid crystals in joint spaces. This leads to a sudden onset of intense pain and swelling in the joints, which also may be warm and very tender. An acute attack commonly occurs at night and can be triggered by stressful events, alcohol or drugs, or the presence of another illness. Attacks usually subside within 3 to 10 days, even without treatment, and the next attack may not occur for months or even years. Over time, however, attacks can last longer and occur more frequently.
- Interval or intercritical gout. This is the period between acute attacks. In this stage, a person does not have any symptoms.
- Chronic tophaceous gout. This is the most disabling stage of gout. It usually develops over a long period, such as 10 years. In this stage, the disease may have caused permanent damage to the affected joints and sometimes to the kidneys. With proper treatment, most people with gout do not progress to this advanced stage.
When It’s Not Gout, It May Be Pseudogout
Gout is sometimes confused with other forms of arthritis because the symptoms—acute and episodic attacks of joint warmth, pain, swelling, and stiffness—can be similar. One form of arthritis often confused with gout is called pseudogout or calcium pyrophosphate deposition (CPPD). The pain, swelling, and redness of pseudogout can also come on suddenly and may be severe, closely resembling the symptoms of gout. However, the crystals that irritate the joint are calcium phosphate crystals, not uric acid. Therefore, pseudogout is treated somewhat differently and is not reviewed in this publication.
What Causes Gout?
A number of risk factors are associated with hyperuricemia and gout. They include:
- Genetics. Many people with gout have a family history of the disease. Estimates range from 20 to 80 percent.
- Gender and age. It is more common in men than in women and more common in adults than in children.
- Weight. Being overweight increases the risk of developing hyperuricemia and gout because there is more tissue available for turnover or breakdown, which leads to excess uric acid production.
- Alcohol consumption. Drinking too much alcohol can lead to hyperuricemia, because alcohol interferes with the removal of uric acid from the body.
- Diet. Eating too many foods that are rich in purines can cause or aggravate gout in some people.
- Lead exposure. In some cases, exposure to lead in the environment can cause gout.
- Other health problems. Renal insufficiency, or the inability of the kidneys to eliminate waste products, is a common cause of gout in older people. Other medical problems that contribute to high blood levels of uric acid include:
- high blood pressure
- hypothyroidism (underactive thyroid gland)
- conditions that cause an excessively rapid turnover of cells, such as psoriasis, hemolytic anemia, or some cancers
- Kelley-Seegmiller syndrome or Lesch-Nyhan syndrome, two rare conditions in which the enzyme that helps control uric acid levels either is not present or is found in insufficient quantities.
- Medications. A number of medications may put people at risk for developing hyperuricemia and gout. They include:
- Diuretics, which are taken to eliminate excess fluid from the body in conditions like hypertension, edema, and heart disease, and which decrease the amount of uric acid passed in the urine
- Salicylate-containing drugs, such as aspirin
- Niacin, a vitamin also known as nicotinic acid
- Cyclosporine, a medication that suppresses the body’s immune system (the system that protects the body from infection and disease). This medication is used in the treatment of some autoimmune diseases, and to prevent the body’s rejection of transplanted organs.
- Levodopa, a medicine used to support communication along nerve pathways in the treatment of Parkinson’s disease.
Who Is Likely to Develop Gout?
Scientists estimate that 6 million adults age 20 and older report having had gout at some time in their lives.1 It is rare in children and young adults. Men, particularly those between the ages of 40 and 50, are more likely to develop gout than women, who rarely develop the disorder before menopause. People who have had an organ transplant are more susceptible to gout.
How Is Gout Diagnosed?
Gout may be difficult for doctors to diagnose because the symptoms can be vague, and gout often mimics other conditions. Although most people with gout have hyperuricemia at some time during the course of their disease, it may not be present during an acute attack. In addition, having hyperuricemia alone does not mean that a person will get gout. In fact, most people with hyperuricemia do not develop the disease.
To confirm a diagnosis of gout, a doctor may insert a needle into an inflamed joint and draw a sample of synovial fluid, the substance that lubricates a joint. The joint fluid is placed on a slide and examined under a microscope for uric acid crystals. Their absence, however, does not completely rule out the diagnosis.
The doctor also may find it helpful to look for uric acid crystals around joints to diagnose gout. Gout attacks may mimic joint infections, and a doctor who suspects a joint infection (rather than gout) may also culture the joint fluid to see whether bacteria are present.
Signs and Symptoms of Gout
- presence of uric acid crystals in joint fluid
- more than one attack of acute arthritis
- arthritis that develops in a day, producing a swollen, red, and warm joint
- attack of arthritis in only one joint, often the toe, ankle, or knee.
How Is Gout Treated?
With proper treatment, most people who have gout are able to control their symptoms and live productive lives. Gout can be treated with one or a combination of therapies. The goals of treatment are to ease the pain associated with acute attacks, to prevent future attacks, and to avoid the formation of tophi and kidney stones. Successful treatment can reduce discomfort caused by the symptoms of gout, as well as long-term damage to the affected joints. Treatment will help to prevent disability due to gout.
The most common treatments for an acute attack of gout are nonsteroidal anti-inflammatory drugs (NSAIDs), taken orally (by mouth), or corticosteroids, which are taken orally or injected into the affected joint. NSAIDs reduce the inflammation caused by deposits of uric acid crystals, but have no effect on the amount of uric acid in the body.
What Can People With Gout Do to Stay Healthy?
Fortunately, gout can be controlled. People with gout can decrease the severity of attacks and reduce their risk of future attacks by taking their medications as prescribed. Acute gout is best controlled if medications are taken at the first sign of pain or inflammation. Other steps you can take to stay healthy and minimize gout’s effect on your life include the following:
- Tell your doctor about all the medicines and vitamins you take. He or she can tell you if any of them increase your risk of hyperuricemia.
- Plan follow-up visits with your doctor to evaluate your progress.
- Drink plenty of nonalcoholic fluids, especially water. Nonalcoholic fluids help remove uric acid from the body. Alcohol, on the other hand, can raise the levels of uric acid in your blood.
- Exercise regularly and maintain a healthy body weight. Lose weight if you are overweight, but avoid low-carbohydrate diets that are designed for quick weight loss. When carbohydrate intake is insufficient, your body can’t completely burn its own fat. As a consequence, substances called ketones form and are released into the bloodstream, resulting in a condition called ketosis. After a short time, ketosis can increase the level of uric acid in your blood.
- Avoid foods that are high in purines.
- beef kidneys
- dried beans and peas
- game meats