What Is Gout?
Gout is one of the most painful rheumatic
diseases. It results from deposits of
needle-like crystals of uric acid in
connective tissue, in the joint space
between two bones, or in both. These
deposits lead to inflammatory arthritis,
which causes swelling, redness, heat,
pain, and stiffness in the joints. The
term arthritis refers to more than 100
different rheumatic diseases that affect
the joints, muscles, and bones, as well as
other tissues and structures. Gout
accounts for approximately 5 percent of
all cases of arthritis.
Pseudogout is sometimes confused with gout
because it produces similar symptoms of
inflammation. However, in this condition,
also called chondrocalcinosis, deposits
are made up of calcium phosphate crystals,
not uric acid. Therefore, pseudogout is
treated somewhat differently and is not
reviewed in this booklet.
Uric acid is a substance that results from
the breakdown of purines, which are part
of all human tissue and 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
the body increases its 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 is not dangerous. However, if
excess uric acid crystals form as a result
of hyperuricemia, gout can develop. The
excess crystals build up in the joint
spaces, causing inflammation. Deposits of
uric acid, called tophi (singular:
tophus), can appear as lumps under the
skin around the joints and at the rim of
the ear. In addition, uric acid crystals
can collect in the kidneys and cause
kidney stones.
For many people, gout initially affects
the joints in the big toe. Sometime during
the course of the disease, gout will
affect the big toe in about 75 percent of
patients. It also can affect the instep,
ankles, heels, knees, wrists, fingers, and
elbows. The disease can progress through
four stages:
Asymptomatic (without symptoms)
hyperuricemia--In this stage, a person has
elevated levels of uric acid in the blood
but no other symptoms. A person in this
stage does not usually require treatment.
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. Early 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
and has normal joint function.
Chronic tophaceous gout--This is the most
disabling stage of gout and usually
develops over a long period, such as 10
years. In this stage, the disease has
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.
What Causes Gout?
A number of risk factors are related to
the development of hyperuricemia and
gout:
Genetics may play a role in determining a
person's risk, since up to 18 percent of
people with gout have a family history of
the disease.
Gender and age are related to the risk of
developing gout; it is more common in men
than in women and more common in adults
than in children.
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.
Drinking too much alcohol can lead to
hyperuricemia because it interferes with
the removal of uric acid from the body.
Eating too many foods rich in purines can
cause or aggravate gout in some people.
An enzyme defect that interferes with the
way the body breaks down purines causes
gout in a small number of people, many of
whom have a family history of gout.
Exposure to lead in the environment can
cause gout.
Some people who take certain medicines or
have certain conditions are at risk for
having high levels of uric acid in their
body fluids. For example, the following
types of medicines can lead to
hyperuricemia because they reduce the
body's ability to remove uric acid:
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;
Salicylates, or anti-inflammatory
medicines made from salicylic acid, such
as aspirin;
The vitamin niacin, also called nicotinic
acid;
Cyclosporine, a medicine used to suppress
the body's immune system (the system that
protects the body from infection and
disease) and control the body's rejection
of transplanted organs; and
Levodopa, a medicine used to support
communication along nerve pathways in the
treatment of Parkinson's disease.
Who Is Likely To Develop Gout?
Gout occurs in approximately 840 out of
every 100,000 people. It is rare in
children and young adults. Adult 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 may be
vague, and they often mimic 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. A
laboratory technician places some of the
fluid on a slide and looks for monosodium
urate crystals under a microscope. Their
absence, however, does not completely rule
out the diagnosis. The doctor also may
find it helpful to examine chalky, sodium
urate deposits (tophi) around joints to
diagnose gout. Gout attacks may mimic
joint infections, and a doctor who
suspects a joint infection (rather than
gout) may check for the presence of
bacteria.
Signs and Symptoms of Gout
Hyperuricemia
Presence of uric acid crystals in joint
fluid
More than one attack of acute arthritis
Arthritis that develops in 1 day,
producing a swollen, red, and warm joint
Attack of arthritis in only one joint,
usually the toe, ankle, or knee
How Is Gout Treated?
With proper treatment, most people with
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
both the discomfort caused by the symptoms
of gout and long-term damage of the
affected joints. Treatment will help to
prevent disability due to gout.
The most common treatments for an acute
attack of gout are high doses of
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.
The NSAIDs most commonly prescribed for
gout are indomethacin (Indocin*) and
naproxen (Anaprox, Naprosyn), which are
taken orally every day. Corticosteroids
are strong anti-inflammatory hormones. The
most commonly prescribed corticosteroid is
prednisone. Patients often begin to
improve within a few hours of treatment
with a corticosteroid, and the attack
usually goes away completely within a week
or so.
* Brand names included in this booklet are
provided as examples only, and their
inclusion does not mean that these
products are endorsed by the National
Institutes of Health or any other
Government agency. Also, if a particular
brand name is not mentioned, this does not
mean or imply that the product is
unsatisfactory.
When NSAIDs or corticosteroids do not
control symptoms, the doctor may consider
using colchicine. This drug is most
effective when taken within the first 12
hours of an acute attack. Doctors may ask
patients to take oral colchicine as often
as every hour until joint symptoms begin
to improve or side effects such as nausea,
vomiting, abdominal cramps, or diarrhea
make it uncomfortable to continue the
drug.
For some patients, the doctor may
prescribe either NSAIDs or oral colchicine
in small daily doses to prevent future
attacks. The doctor also may consider
prescribing medicine such as allopurinol
(Zyloprim) or probenecid (Benemid) to
treat hyperuricemia and reduce the
frequency of sudden attacks and the
development of tophi.
What Can People With Gout Do To Stay
Healthy?
To help prevent future attacks, take the
medicines your doctor prescribes.
Carefully follow instructions about how
much medicine to take and when to take it.
Acute gout is best treated when symptoms
first occur.
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 followup visits with your doctor to
evaluate your progress.
Maintain a healthy, balanced diet; avoid
foods that are high in purines; and drink
plenty of fluids, especially water. Fluids
help remove uric acid from the body.
Exercise regularly and maintain a healthy
body weight. Lose weight if you are
overweight, but do not go on diets
designed for quick or extreme loss of
weight because they increase uric acid
levels in the blood.
What Research Is Being Conducted To Help
People With Gout?
Scientists are studying which NSAIDs are
the most effective gout treatments, and
they are analyzing new compounds to
develop safe, effective medicines to lower
the level of uric acid in the blood and to
treat symptoms. They also are studying the
structure of the enzymes that break down
purines in the body to achieve a better
understanding of the enzyme defects that
can cause gout.
Scientists are studying the effect of
crystal deposits on cartilage cells for
clues to treatment. They also are looking
at the role of calcium deposits in
pseudogout in the hope of developing new
treatments. The role genetics and
environmental factors play in
hyperuricemia also is being investigated.
Where Can People Find More Information
About Gout?
National Institute of Arthritis and
Musculoskeletal and Skin Diseases (NIAMS)
National Institutes of Health
1 AMS Circle
Bethesda, MD 20892-3675
Phone: 301-495-4484 or 877-22-NIAMS
(226-4267) (free of charge)
TTY: 301-565-2966
Fax: 301-718-6366
E-mail:
NIAMS
Info@mail.nih.gov
www.niams.nih.gov
NIAMS provides information about various
forms of arthritis and rheumatic diseases
and bone, muscle, joint, and skin
diseases. It distributes patient and
professional education materials and also
refers people to other sources of
information. Additional information and
updates can be found on the NIAMS Web
site.
American College of
Rheumatology/Association of Rheumatology
Health Professionals
1800 Century Place, Suite 250
Atlanta, GA 30345-4300
Phone: 404-633-3777
Fax: 404-633-1870
www.rheumatology.org
This association provides referrals to
rheumatologists. The organization also
provides educational materials and
guidelines about many different rheumatic
diseases.
Arthritis Foundation
1330 West Peachtree Street
Atlanta, GA 30309
Phone: 404-872-7100 or 800-283-7800 (free
of charge)
or call your local chapter (listed in the
phone directory)
www.arthritis.org
