From the Research
Urate and uric acid are essentially the same substance in different forms, with uric acid being the protonated form and urate being the ionized form that predominates at the normal physiological pH of the body. The distinction between urate and uric acid is important in understanding how this substance behaves in the body, particularly in relation to conditions like gout or kidney stones 1. At the normal blood pH of 7.4, about 98% of uric acid exists as urate, and both terms are often used interchangeably in clinical settings when discussing these conditions.
The key difference between urate and uric acid lies in their solubility, with urate being more soluble than uric acid. This is why acidic urine can promote uric acid stone formation, as more of the substance exists in the less soluble uric acid form 1. When blood tests measure "uric acid levels," they're actually measuring the total concentration of both forms combined.
In clinical practice, the terms urate and uric acid are often used to describe the same condition, such as hyperuricaemia, which is characterized by a high level of urate in the blood 2. The management of gout, a common inflammatory arthritis caused by the deposition of monosodium urate crystals, involves the use of urate-lowering therapies, such as allopurinol and febuxostat, to reduce the concentration of uric acid in the blood 3, 4.
Some key points to consider when discussing urate and uric acid include:
- The interchangeable use of the terms urate and uric acid in clinical settings
- The importance of understanding the distinction between urate and uric acid in relation to conditions like gout or kidney stones
- The role of urate-lowering therapies in the management of gout
- The need to consider the solubility of urate and uric acid when interpreting blood test results or managing conditions like kidney stones.
Overall, the distinction between urate and uric acid is important in understanding how this substance behaves in the body, and both terms are often used interchangeably in clinical settings.