Kidney tests

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.

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

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.

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

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