First paragraph: Progressive loss of kidney function is often described as chronic kidney disease (CKD). Chronic kidney disease may progress to end stage renal failure (ESRF), at which point the kidneys are not able to perform their regulatory and excretory functions. The transition into end-stage renal failure, with the concomitant derangement of normal biochemical, metabolic and endocrine functions, is almost always accompanied by the clinical syndrome of uraemia. Symptoms such as anorexia, generalised lethargy and fatigue, sleep disorder, neurological dysfunction, nausea and vomiting are frequently evident. The appearance of these symptoms is remarkably consistent and appears to coincide with abnormal plasma levels of many substances including urea, creatinine, phosphate, and parathyroid hormone, which have been identified as potential uraemic toxins. Accompanying clinical signs of ESRF include fluid retention (peripheral and pulmonary oedema), raised blood pressure, diminishing haemoglobin levels and abnormal biochemistry (creatinine, serum urea and potassium) (Bommer 1992, Moore 2000)