A product of protein metabolism, its elimination removes excess nitrogen from the body. It is the most important indicator in the diagnosis of uratic arthritis. When concentrations are normal, uric acid in the extracellular media (joint fluid) has a liquid consistency. However, when the normal limit is exceeded, the uric acid begins to crystallise. These crystals are deposited in the joints, causing severe pain (uratic arthritis). The aim of uratic arthritis treatment is precisely to reduce acid levels to certain constants so that the crystals begin to dissolve.

There are two fundamental reasons for the increase in uric acid concentration: delayed excretion (kidney malfunction) and overproduction, which is very rare.

The uric acid content in patients with gout has a fluctuating course: it periodically reaches normal values, then increases up to 4 times. It is worth noting that in 40% of patients during an acute attack of uratic arthritis pain, uratic arthritis levels may be normal.

In order to obtain objective data (determination of acid that is formed in the body and not taken in with food) it is necessary to appoint a protein-free diet three days before the test.

Patients who prefer protein-containing foods (meat, beans, liver) or, conversely, who do not eat these foods, have higher or lower uric acid concentrations, respectively.