Urea and Electrolytes Test

U&E is often used as a screening test for patients who are generally unwell, to detect abnormalities of blood chemistry, including kidney failure and dehydration.

How the Test is Performed

The U&E test is a blood test and requires a few millilitres of blood from a vein. In newborn babies blood may be taken from a heel-prick sample.

Medical Conditions and Symptoms

U&E is usually performed to confirm normal kidney function (renal function) or to exclude a serious imbalance of biochemical salts in the bloodstream. A diverse number of conditions may be detected on the U&E test, as each parameter tested may be high or low. These conditions include:

hyponatraemia (low sodium)
hypernatraemia (high sodium)
hypokalaemia (low potassium)
hyperkalaemia (high potassium)
metabolic acidosis (low bicarbonate)
metabolic alkalosis (high bicarbonate)
dehydration (high urea and/or creatinine)
renal (kidney) impairment or failure (high urea and/or creatinine)
gastrointestinal bleeding (high urea)
hypoglycaemia (low glucose)
hyperglycaemia (high glucose)

Each of these conditions in turn have several possible causes.

Test Results Explained

Related Specialists

Related Procedures

Pre-operative Anaesthetic assessment

Related Tests

Sodium (Na)
Potassium (K)
Chloride (Cl)
Biocarbonate (HCO₃, Bicarb)
Urea (U)
Creatinine (Cr)
Glucose (glu)

Also Known As

Urea, Electrolytes & Creatinine (UEC)
Creatinine, Urea, Electrolytes & Glucose (CUEG)
Electrolytes Routine Bichemistry