Uric Acid / Urate

Clinical Biochemistry

Background Information

• Uric acid (urate) is produced following breakdown of purines (either from the diet or from the normal breakdown of cells in the body). Uric acid is removed by the kidneys and excreted in the urine and faeces.
• Uric acid is measured in patients with inflammatory arthropathies, although not all patients with hyperuricaemia have (or will develop) gout. The diagnosis depends on the demonstration of synovial fluid uric acid crystals in the presence of inflammatory cells.
• Uric acid is also used for the investigation/monitoring of pre-eclampsia and sometimes following chemotherapy or radiation treatment.
• Elevated uric acids levels will be seen in renal failure. Raised levels are also seen with excessive use of alcohol, starvation, a high-protein diet and strenuous exercise.
• Elevated levels are also seen in the rare inherited disorder, Lesch-Nyhan syndrome.
• Low uric acid levels may indicate severe liver disease, low protein diet, heavy metal poisoning, Wilson's disease or some type of cancer.
• Many drugs can affect uric acid levels. For example, raised levels are caused by thiazide diuretics, theophylline and low dose aspirin; low levels are caused by high dose aspirin, corticosteroids and allopurinol.
• Rasburicase is given to reduce uric acid levels in tumour lysis syndrome. It continues to breakdown uric acid in the collected blood sample and measured levels may not represent circulating levels. See specific sample requirements below.

Patient Preparation

No specific patient preparation is required.

Sample Requirements

For patients on rasburicase, see additional requirements below.

For adults, blood taken into a 5mL gold top gel tube (or rust top for the Acute Unit)

For children, blood taken into a 3.5mL rust top gel tube

For neonates, blood taken into a 0.8mL minicollect lithium heparin tube.

Storage/Transport

Store refrigerated if unable to send to the laboratory the same day. Transport as soon as possible at ambient temperature.

Required Information

Include relevant clinical details, relevant drugs, known or possible diagnoses and whether the patient is pregnant (including the stage of pregnancy).

Turnaround Times

The assays are run throughout the day and night. The in-lab turnaround time is always less than 24 hours. The test can be ordered as an urgent request.

Reference Ranges

Further information

To learn more about uric acid, visit Lab Tests Online

For local guidance on Tumour Lysis Syndrome prevention and management, see the Trust Guideline.

Page last updated: 05/11/2025 | Page last reviewed: 05/11/2025