Gout is a very painful form of arthritis that can develop when blood levels of uric acid are chronically high. Uric acid is a substance that normally forms when the body breaks down substances called purines, which are found in the body and consumed in foods.
People with gout either produce too much uric acid or their body has a problem removing it. Gout can occur on its own but it is more often associated with other medical conditions or medications that may interfere with the body's ability to remove uric acid.
This buildup of uric acid (hyperuricemia) can lead to the development of sharp, needle-like crystals, which can accumulate in the body’s connective tissues. These deposits of uric acid crystals produce swelling, redness, heat, pain and stiffness in the joints.
Joints are most often affected, but uric acid crystals can also accumulate under the skin and in the kidneys and urinary tract. The symptoms of gout are usually severe and can occur without warning, often at night. Such occurrences are called acute gouty arthritis. Symptoms include inflammation, redness and severe joint pain. The large joint of the big toe is usually affected first.
Symptoms may initially disappear within three to 10 days, but if left untreated, gout can lead to increasing pain and joint damage. In some cases, the function of the kidneys and the urinary tract can be affected. People with gout are also more likely to develop kidney stones and other complications.
However, not everyone with high levels of uric acid will develop gout. Although it is not known why some people develop gout and not others, risk factors include family history of gout, excessive consumption of alcohol, diet, frequent use of some medications, and medical conditions including obesity, heart disease, kidney disease and diabetes. In addition, men are much more likely than women to develop gout. Some people may develop gout even with normal levels of uric acid in the blood.
Treatment focuses on reducing joint inflammation, preventing further episodes of acute gouty arthritis and decreasing the high blood levels of uric acid with medication and lifestyle changes (e.g., maintaining a healthy weight, avoiding alcohol and foods high in purines such as organ meats and sardines).
Gout is highly treatable. Most patients who receive prompt treatment and follow guidelines can relieve attacks and sometimes avoid an impending attack. But repetitive attacks can permanently damage joints.
About gout
Gout is one of the most painful forms of arthritis. It usually develops when there are chronically high levels of uric acid in the blood. Uric acid is the waste product formed from the breakdown of purines. Purines are substances found in all of the body's tissues as well as in many foods, such as organ meats and seafood.
The uric acid can form into sharp, needle-like crystals that accumulate in the body’s connective tissues, particularly in the joint space between the bones. These deposits of uric acid crystals (called monosodium urate crystals or MSU) produce swelling, redness, heat, pain and stiffness in the joints. The joints are the most commonly affected part of the body, but crystals can also form beneath the skin (called tophi) and in the kidneys (kidney stones) or other parts of the urinary system.
Uric acid normally dissolves in the blood and passes through the kidneys before being eliminated in the urine. People with gout either produce excessive levels of uric acid or their kidneys have a problem eliminating it. This condition is called hyperuricemia and occurs when uric acid reaches or exceeds 7 milligrams/deciliter in the blood. Not all people with hyperuricemia develop gout, and some patients who do develop gout have normal blood levels of uric acid. The reason for this is not thoroughly understood.
Elevated levels of uric acid also increase the risk of fatal heart disease, according to long-term research using data from the National Health and Nutrition Examination Survey (NHANES).
Gout can be primary or secondary. Primary gout occurs on its own and is due to the body’s overproduction of purines in the liver or an inherent inability to eliminate purines in the urine. Primary gout is uncommon.
Secondary gout, which is much more common, is due to an underlying medical condition or the therapy to treat a medical condition. For instance, diuretics (medications used to treat high blood pressure and other conditions) help flush water from the body. These medications can retain uric acid, thus causing levels of uric acid to rise.
Gout is sometimes confused with another form of arthritis called pseudogout because it produces similar symptoms of inflammation and swelling. However, in the latter condition, deposits are made up of calcium phosphate crystals rather than uric acid.
Up to 3 million Americans have gout, according to the American College of Rheumatology. Gout is rare in children and young adults. It is more prevalent in men than women.
Gout is highly treatable. If left untreated, however, it can erode the joints and bones and cause disfigurement. In addition, patients with gout have an increased risk for developing kidney stones because uric acid crystals can also collect in the urinary tract and kidneys, which can impair kidney function.
If gout is properly diagnosed and treated early, most patients experience relief from their symptoms. Patients are advised to seek medical treatment with a rheumatologist because these physicians specialize in the management of gout and other forms of arthritis.
Risk factors and causes of gout
Gout, one of the most painful types of arthritis, is often caused by excessive blood levels (above 7 milligrams/deciliter in females and 8 milligrams/deciliter in males) of uric acid (hyperuricemia). But not all people with hyperuricemia will develop gout, and not all people with gout have hyperuricemia. In many cases, the cause of gout is unknown (idiopathic).
Many common conditions are strongly associated with gout, including diabetes, high blood pressure, heart disease, obesity, kidney disease and dyslipidemia (unhealthy levels of cholesterol and other blood fats). In addition, episodes of acute gouty arthritis can be triggered by a number of factors, including stress, minor trauma, infection, heavy consumption of alcohol and surgery. Research suggests that hot, humid weather and dehydration may also trigger attacks.
Physicians have identified the following risk factors for gout:
Family history. Some people are born with an enzyme defect that makes it hard for the body to break down purines. According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, about 18 percent of gout patients have a family history of the disease.
Sex and age. Gout occurs more often in men than in women, mostly because women tend to have lower levels of uric acid than men. However, after menopause, women’s levels of uric acid are similar to those of men.
In addition, men are more likely to develop gout earlier, usually between the ages of 30 and 50. Women who develop gout generally do so after menopause. This may be especially true if women are prescribed certain medications, such as diuretics for high blood pressure, heart failure, kidney disease or other conditions.
Excessive consumption of alcohol. Drinking too much alcohol, especially beer, can interfere with the body’s ability to eliminate uric acid, as well as introduce more purines (which break down into uric acid) into the diet. Some research has also linked heavy consumption of sugary soft drinks to increased risk of gout.
Excessive consumption of foods rich in purines (e.g., organ meats, meats, seafood). Eating too much of these foods may cause high blood levels of uric acid.
Long-term use of certain medications. Many medications have been shown to interfere with the body’s ability to eliminate uric acid, often because they affect kidney function, including diuretics, aspirin, levodopa (a treatment for Parkinson’s disease) and immunuosuppressives, such as those taken after an organ transplant.
In addition, chemotherapy for cancer increases the break down of abnormal cells, releasing large amounts of purines into the body that can cause accumulation of uric acid in the blood.
Genetics. Researchers in 2008 identified three genes that together may increase the risk of gout by up to 40 times: SCLA29, ABCG2 and SLC17A3.
Anemia. A condition in which the number and volume of red blood cells and the amount of hemoglobin in the blood are lower than normal.
Lymphoproliferative disorders. Conditions in which cells of the lymphatic system grow excessively, such as leukemia or lymphoma.
Paget's disease. A chronic disorder that may result in enlarged or deformed bones.
Psoriasis. A common skin inflammation characterized by redness, itching, and thick, dry, silvery scales on the skin.
Exposure to lead. Some studies have linked environmental exposure to lead with gout.
Signs and symptoms of gout
Generally, gout progresses through four stages. During the first stage, a patient has elevated levels of uric acid in the blood (hyperuricemia) but no other signs or symptoms. At this stage, called asymptomatic hyperuricemia, patients seldom require treatment. In addition, not all people with hyperuricemia go on to develop gout.
The second stage of gout is called acute gouty arthritis. It occurs when the patient suddenly experiences a hot, red, swollen joint, caused by the formation of uric acid crystals between the joints. In most cases, the big toe (a condition once known as podagra) or the knee is affected.
The attack often occurs at night and in a single joint, with the pain becoming more severe. When a single joint is involved, the condition is called monoarticular gout. The pain may grow so intense that even a bed sheet on the joint can cause pain. Chills and a mild fever along with a general feeling of malaise may also accompany the severe pain and inflammation.
Monoarticular gout occurs more often in middle-aged patients and usually involves one joint in the lower limbs, especially the big toe (hallux).
Even without treatment, the first episode often disappears spontaneously within three to 10 days, but prompt treatment can abort the attack in a few hours. Although the pain and swelling disappear, gouty arthritis almost always returns in the same joint or in another one.
A patient is usually symptom-free for a period of time. During this third stage, called interval or intercritical gout, a patient does not have any symptoms and has normal function of the joints. The next attack usually occurs within two years, followed by additional attacks thereafter.
If left untreated, the interval between attacks may shorten and they may become increasingly severe and prolonged. Over time, the attacks can begin to involve multiple joints at once – called polyarticular gout – and may be accompanied by a joint infection (e.g., septic arthritis). Polyarticular gout occurs more often in elderly patients and usually involves the joints in the upper extremities, especially the fingers.
In addition, episodes of acute gouty arthritis can be triggered by circumstances that affect blood levels of uric acid, such as certain chronic illnesses (e.g., diabetes, high blood pressure), injury, surgery, fasting, drinking alcohol, overeating (especially foods rich in purines, such as liver) and taking certain medications (e.g., diuretics, aspirin, immunosuppressives).
People who experience sudden, intense joint pain with fever should see their physician as soon as possible. If gout is left untreated, it can lead to worsening of the pain and permanent joint damage.
When gout goes untreated for several years, it can progress to a condition called chronic tophaceous gout. During this last phase, patients experience chronic pain and inflammation and there is permanent joint damage due to the formation of large masses of uric acid crystals, which also collect in bone and cartilage, such as in the ears. These masses or nodules of crystals are called tophi. They can form near the knuckles and small joints of the fingers and can cause disfigurement. These large masses or lumps may drain and ooze a chalky substance.
Diagnosis methods for gout
Diagnosis of gout usually begins with a physical examination and questions about personal and family medical history. A physician may suspect gout if a patient has had a history of acute arthritis, especially in big toe, that has been followed by a period when symptoms have disappeared.
To confirm gout as well as rule out other diseases with similar symptoms (e.g., pseudogout, septic arthritis, rheumatoid arthritis), a physician may perform an arthrocentesis. This procedure uses a needle to withdraw (aspirate) fluid from a joint so the sample can be examined for uric acid crystals. Gout crystals are needle-shaped and are negatively birefringent (unable to split a ray of light in two) under a polarized light microscope, as compared to pseudogout, where crystals are positively birefringent. During an acute attack, the crystals are often present inside white blood cells.
Large deposits of uric acid crystals (tophi) may be removed from beneath the skin in a biopsy to diagnose an advanced stage of gout called chronic tophaceous gout, though this procedure is not commonly performed for diagnosis.
Other tests may include:
Urinalysis. Laboratory analysis of urine samples to measure the amount of uric acid being eliminated by the kidneys. This test is also performed to detect kidney stones.
Blood tests. Laboratory analysis of blood samples to measure uric acid in the blood and detect hyperuricemia, which is present in most cases of gout. Hyperuricemia is defined as more than 7 milligrams of uric acid per deciliter of blood. However, some patients with gout may have normal levels of uric acid, so hyperuricemia is not used to definitively diagnose gout. Blood tests are also used to rule out other arthritic conditions.
X-ray. This imaging test is primarily used to assess joint damage, especially in patients who have had multiple episodes of acute gouty arthritis.
Once a diagnosis has been made, treatment should be started immediately to avoid long-term complications of untreated gout, such as chronic tophaceous gout, kidney stones and kidney damage. Sometimes it becomes difficult to diagnose gout clinically, especially if it affects an atypical joint in the beginning and the person has normal values of uric acid.
Treatment options for gout
Rheumatologists will often be involved in the treatment of gout because they specialize in managing this and other forms of arthritis.
A number of medications may be recommended to reduce joint pain and inflammation. To avoid any interactions, patients must advise their physicians if they are taking other drugs.
Medications to treat gout include:
Nonsteroidal anti-inflammatory drugs (NSAIDs). High doses of NSAIDs such as indomethacin or ibuprofen are the most common treatment for acute gouty arthritis. However, aspirin should not be used for this condition because it can elevate levels of uric acid in the blood. Patients who have a history of ulcers or kidney problems, or those taking anticoagulant medication, may be treated with another type of anti-inflammatory medication, or other medications may be used in conjunction with NSAIDs to protect against unwanted side effects.
Corticosteroids. These medications are strong anti-inflammatory hormones, which may be given to patients who cannot use NSAIDs. Corticosteroids may be given in pill form (in high doses) or via injections into the swollen joint. Patients usually begin to improve within a few hours of treatment, and the attack often completely subsides within a week or so. When used long term, however, these medications may produce side effects, such as weight gain, osteoporosis (bone thinning), cataracts, glaucoma and diabetes, and may contribute to hardening of the arteries (atherosclerosis).
Colchicine. This alkaloid drug is often prescribed when NSAIDs or corticosteroids do not control symptoms. However, it is most effective when taken within the first 12 hours of an episode of acute gouty arthritis. Physicians may prescribe it as often as every hour until joint pain and inflammation begin to improve. When taken orally, side effects may include nausea, vomiting, abdominal cramps or diarrhea.
In addition, colchicine may also be prescribed in low doses to prevent further attacks. When taken in low doses, side effects are less likely to occur. Even though the chronic use of colchicine can reduce or prevent attacks of gout, it does not prevent the accumulation of uric acid crystals that can cause joint damage even without attacks of hot, swollen joints.
Colchicine may also be administered intravenously (I.V.), but this form of therapy should be performed only by a physician experienced in it. When done improperly, I.V. colchicine therapy can have severe side effects, including bone marrow toxicity, kidney failure and, in some cases, even death.
Once the acute gouty arthritis is under control, treatment for gout focuses on preventing recurrent attacks and decreasing the levels of uric acid in the blood. Therapy to lower blood levels of uric acid, which may lead to the formation of uric acid crystals in the tissues and joints of the body, may include:
Uricosurics. These medications help the kidneys eliminate excess uric acid in the urine. Uricosurics should be taken with plenty of fluid (at least 68 ounces or 2 liters a day) to prevent the formation of uric acid kidney stones. These drugs are usually prescribed when gout is caused by under-excretion of uric acid, which occurs in most cases. However, uricosurics should not be used by patients with reduced kidney function or those with tophaceous gout.
Xanthine oxidase inhibitors. These drugs, including allopurinol, decrease the body's production of uric acid and are the most reliable way to lower levels of uric acid in the blood. Common side effects include stomach pain, headache, diarrhea and rashes. In very rare cases, some people can develop an extremely severe allergic reaction that can lead to kidney and liver toxicity as well as become life-threatening. Patients who develop a rash or a fever after use of a xanthin oxidase inhibitor should seek immediate medical care.
To be effective, medications to reduce uric acid in the blood must be taken regularly and long-term. Stopping the medications often results in recurrence of gout later.
In addition, medications to treat hyperuricemia (high blood levels of uric acid) should not be administered during an episode of acute gouty arthritis because they may intensify and/or prolong the attack. They should be administered only after symptoms (e.g., joint pain and inflammation) subside.
In instances of medication-induced hyperuricemia, switching medications under a physician's supervision is often the only course of action necessary.
Surgery is rarely needed for gout unless significant joint damage has occurred from lack of effective and timely treatment. Sometimes surgery may be performed to remove large tophi that are draining (oozing), infected or interfere with normal joint movement. In very severe cases, patients may have to undergo joint replacement surgery (arthroplasty).
Treatment for gout should begin early to prevent long-term complications, such as chronic tophaceous gout, the formation of kidney stones and kidney damage. In secondary gout, treatment of the primary condition causing gout may control the disease.
Prevention methods for gout
In general, keeping uric acid within a normal range (under 7 milligrams/deciliter) is the long-term key to preventing buildup of uric acid, which may lead to gout and/or bouts of acute gouty arthritis (episodes of severe joint pain and swelling) in people diagnosed with the disease. This can be achieved by:
Maintaining a healthy body weight. Patients can achieve and maintain a healthy body weight by eating a balanced diet and exercising regularly.
Avoiding excessive consumption of foods rich in purines. It should be noted that all meat, fish and poultry contain moderate amounts of purines. However, some are more rich in these substances than others, such as:
Legumes and vegetables (e.g., beans, peas, mushrooms, cauliflower, spinach)
Limiting or avoiding alcohol. Drinking excessive amounts of alcohol, especially beer, can inhibit the elimination of uric acid and cause dehydration, which in turn may lead to gout. Also, if a patient is experiencing a gout attack, it is best to abstain from alcohol to prevent worsening of symptoms.
Drinking plenty of fluids (at least 68 ounces or 2 liters a day). Fluids help dilute uric acid in the blood and urine. It is especially important for gout patients to avoid dehydration during hot and humid weather.
Avoiding use of the inflamed joint during an acute attack until pain and inflammation disappear.
Limited research has suggested that eating cherries might help prevent or relieve gout. Additional studies would be needed to establish this connection. The U.S. Food and Drug Administration (FDA) has warned companies not to market juice and other cherry products as a treatment or preventive measure for gout, other forms of arthritis or other diseases.
When gout is properly treated, the prognosis is excellent, and many patients experience relief from their symptoms and live productive lives.
Questions for your doctor regarding gout
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about gout:
If I have hyperuricemia, does it mean I will get gout?
Am I at risk of developing gout?
Will eating a high-protein diet put me at risk for gout?
Are there specific foods I should avoid?
What test for gout might I undergo, and what do these tests involve?
What are my treatment options for gout?
How long will my treatment last?
Are there any side effects associated with my therapy for gout?
What things should I avoid while undergoing treatment for gout?
Is there any way I can prevent gout?
Do high levels of uric acid increase my risk of heart disease or other conditions in addition to gout?
