Kidney tests

Chloride is an electrolyte that is important for normal cell function and regulation of fluid and salt balance in the body. It is part of the stomach's hydrochloric acid and contributes to food digestion.

Creatinine is formed in your muscles when the body breaks down creatine phosphate (the muscles' energy reserve). The kidneys' job is to filter creatinine.

Cystatin C is a protein produced by all cells in the body and filtered by the kidneys. Measuring cystatin C levels can give an indication of kidney function.

eGFR is a marker of kidney function, a low eGFR (estimated glomerular filtration rate) may indicate impaired kidney function.

Phosphate is an additive, it often appears in combination with, for example, sodium and calcium which form salts - these are called phosphates.

Renin is an enzyme from the kidneys that starts the RAAS system and affects blood pressure, fluid volume and salt balance. Measurement of P-Renin, usually together with aldosterone, is used in the investigation of high blood pressure and suspected disorders of the RAAS.

Urate or uric acid is a naturally occurring chemical compound produced in the kidneys and intestines and excreted when the body breaks down substances called purines.

Urea is a residual product that is formed during the breakdown of proteins and amino acids from the food we put into us