Diagnosing Gout

Diagnosing Gout

Gout, a type of arthritis, occurs when too much of a substance called uric acid builds up in the blood; this condition is also called hyperuricemia. Uric acid can come from the breakdown of old cells and from certain foods and drinks. If too much uric acid is produced, or if it isn’t properly excreted, it can form tiny crystals that are deposited in soft tissues and joints. For this reason, gout is called a “crystal deposit disease.”

Gout Diagnosis: The Importance of Getting It Right

Many types of inflammatory arthritis, including gout, produce hot, stiff, inflamed, and painful joints. But just because someone has these symptoms doesn’t necessarily mean that it’s gout.

It is vital that a patient gets a proper diagnosis, says Lawrence Brent, MD, head of the division of rheumatology at the Albert Einstein Medical Center in Philadelphia: “Gout is a chronic disease and can lead to long-term damage.”

Gout Diagnosis: Looking for Crystals

“The first thing we use to make an accurate diagnosis is a patient’s history,” says Dr. Brent. Your age, sex, family history, weight, and diet are all risk factors for gout. Kidney and cardiovascular problems, as well as medications taken for these and other conditions, can also be associated with gout.

The true determinant comes with a test to look for the hallmark sign of gout, uric acid crystals.

Visiting your doctor during an attack can ensure an accurate diagnosis. “The best way to confirm gout is to get joint fluid during an acute attack so you can identify the uric acid crystals,” Brent says. The fluid is examined under a microscope with special filters so the crystals, if there are any, show up.

This procedure involves draining fluid out of the inflamed area. Patients may worry that this will hurt, but Brent says, “In general it’s only a little bit more painful than drawing blood.”

To handle that pain, Brent’s team uses a spray to numb the skin before the injection. “The procedure is very short, only 30 seconds to a minute,” he says.

Keep in mind that even if crystals aren’t seen in the fluid, gout can’t be ruled out just yet. Further samples may be taken to see if there are crystals in the joints themselves, both those that are inflamed and others that don’t appear affected. If tophi (harder, more permanent uric acid deposits) have developed, these can also be used to find uric acid, or urate, crystals.

Taking fluid from swollen joints can rule out other problems, including inflammation due to infection and swelling caused by different types of crystals, such as those found in the very similar pseudogout.

Gout Diagnosis: Looking for Hyperuricemia

Some people may wonder why a blood test can't be used to diagnose gout.

“That’s not always helpful,” says Brent. “While most people will have elevated uric acid levels at some point during their disease, during a gout attack it’s not unusual for those levels to be normal.” Levels of uric acid may also be checked in a urine sample.

However, you may not develop gout just because you have hyperuricemia. On the other hand, because people with chronic gout often have hyperuricemia when they don’t have acute inflammation, blood tests may be used to monitor whether a medication is doing its job at bringing down uric acid levels.

Gout Diagnosis: Other Signs of Gout

Patients may have other physical signs of gout that last beyond the acute period. In addition to the tophi, which may develop underneath the skin — especially on the elbows and behind the ears, according to Brent — uric acid may also cause kidney stones.

If tophi and perhaps kidney stones have developed, they indicate that gout has been present for a number of years, and the damage may be visible on an X-ray. The longer you go without treatment, the more likely you are to have permanent joint, and even kidney, damage. If you have hot, throbbing, almost unbearable pain in the big toe, contact your doctor. Even if the pain eases in a day or so, gout may be to blame.