What are early signs and symptoms of gout?
Gout attacks, particularly early ones, may appear to come on suddenly, but this is often the result of months or even years of uric acid levels building up in the bloodstream. After a long period of sustained high uric acid levels, it can begin to leave the bloodstream and start forming crystals in the joints and soft tissues.
Gout attacks are often triggered by the body’s immune system responding to the uric acid crystals that have formed in the joints and soft tissue. When immune cells called neutrophils enter the joint to try and eliminate the uric acid crystal, this is when inflammation, redness, pain, and swelling will appear, causing what is known as a gout attack.
Uric acid crystals can build up in multiple joints, but gout attacks are more common in lower limb joints such as the knees, ankles, and particularly the base of the big toe.
Many people will not have any indication they have gout before a first gout attack.
As we go about our daily lives, micro-traumas can occur in our body and joints which may cause neutrophils to rush to those areas to help with the healing process. If your joint already has a buildup of uric acid crystals, this rush of neutrophils sent as part of the regular healing process may also detect the uric acid crystals and start responding to try and get rid of them. This process could trigger a gout attack. Since these micro-traumas are often more common in lower limbs and joints, these areas are more common sites for a gout attack.
Other risk factors for a gout attack are infection, a drastic increase in uric acid levels in the bloodstream — for example following a protein-rich meal, a night of drinking alcohol (especially beer), or a period of dehydration.
What are tophi?
Bumps can form when uric acid crystals build up under the skin. These bumps, called tophi, are usually small and hard and can form anywhere on the body. Often they form on the toes, knees, heels, fingers, ears, forearms or elbows. Tophi are usually painless; however, sometimes they can become inflamed and ooze a thick discharge. Tophi often form several years after the first gout attack and in some cases they appear in people who have never had a gout attack.
How is gout diagnosed?
To diagnose gout, your doctor will ask about recent medications and diet. They will want to know:
when symptoms began
how long symptoms or attacks last
the intensity of your symptoms or attacks
which joints are involved or affected by symptoms
A blood test can determine uric acid levels, but high levels do not necessarily indicate a gout attack. During an active attack, your doctor may send you for blood work to check your uric acid levels. They may ask you to repeat a blood test after your attack has ended, to compare your uric acid levels during and after an attack.
To receive a confirmed diagnosis of gout, your doctor will need to take a fluid sample from your joint during a gout attack. To do this, they will insert a needle into the affected joint and extract a sample.
The sample will then be examined under a microscope to determine if neutrophils are actively trying to destroy the uric acid crystals. If this activity is observed in the fluid sample, your doctor will be able to confirm a gout diagnosis. When neutrophils try to destroy the crystals, the crystals are described as being intracellular.
Although taking a fluid sample is the most definitive way of diagnosing gout, this is not always possible or necessary depending on your situation. Your doctor can also make a presumed diagnosis based on a combination of signs, symptoms, and test results, such as blood work, x-ray, and ultrasound.
This gout resource was reviewed in October 2022 with expert advice from:
Dr. Jean-Philip Deslauriers
Clinical Professor at the University of Sherbrooke
Bathurst, New Brunswick