For centuries, this condition was known as the ‘disease of kings’ — an illness reserved for opulent banquets and overconsumption of meat and wine. However, unlike the royalty of the past, today gout doesn’t choose nobles: anyone can be surprised by this intense joint pain; and what’s the culprit? Uric acid is a tiny molecule with major impact on our body. But what is uric acid? Find out what signs to look out for, the reference ranges and when you should get tested.
What is uric acid?
Uric acid is the end product of purine metabolism. Under normal conditions, purines (natural compounds in cells and some foods) dissolve and circulate in the blood and are eliminated through the kidneys in urine. When purine production increases, elimination decreases, or both phenomena occur simultaneously, the uric acid level in blood rises — hyperuricemia — which can lead to gout (crystal deposits in the joints) and kidney stones.
When should I get tested?
Measuring uric acid can be useful when there are:
- Symptoms in the joints that suggest gout (intense and sudden pain, redness and heat, especially in the big toe, ankle, knee or hands);
- Prior kidney stones or symptoms of renal colic;
- Family history of gout/hyperuricemia;
- Follow-up for kidney disease, hypertension, metabolic syndrome or urate-lowering therapies.
Collection
Ideally, avoid alcohol intake and purine-rich meals for 24 hours before, and maintain good hydration. Fasting is recommended before collection.
Reference ranges
(common examples; may vary according to method /lab):
- Serum, female: 2,4–6,0 mg/dL (143–357 µmol/L)
- Serum, male: 3,4–7,0 mg/dL (202–416 µmol/L)
- Urine 24 h: 0,24–0,75 g/day (1,4–4,5 mmol/day)
Always consult the intervals in your report and your physician’s interpretation.
Frequent causes of high uric acid levels
- High purine foods: offal, some red meats, sardines, anchovies, mackerel; alcohol (especially beer).
- Impaired kidney function: lower urate excretion.
- Genetic factors and drugs (ex. thiazide diuretics).
- Metabolic conditions: abdominal obesity, hypertension, insulin resistance.
What are the risks?
- Gout: urate crystals trigger joint inflammation (attacks) and, if untreated, can lead to tophi (nodules) and chronic joint pain.
- Uric acid nephrolithiasis: crystals/stones that cause pain and associated infection.
- Cardiometabolic alliance: high urate levels are associated with hypertension and insulin resistance; this causal relationship is still under investigation.
