In a proportion of patients, CKD will progress to end stage renal disease (ESRD). This is defined as an irreversible decline in kidney function for which renal replacement therapy (RRT) is required if the patient is to survive. In one UK study, 4% of patients with CKD progressed to develop ESRD requiring RRT over a five and a half year follow up period. The decision to commence RRT takes into account symptoms of biochemical disturbance, in conjunction with the risks and inconvenience of starting RRT. European Best Practice Guidelines recommend that RRT should commence when the estimated Glomerular Filtration Rate (eGFR) falls below 15ml/min/1.73m2 or when symptoms of uraemia, fluid overload or malnutrition are resistant to medical therapy. In an asymptomatic patient, an eGFR of below 6ml/min/1.73m2 would also prompt the initiation of dialysis. It is known that the life expectancy of patients receiving RRT is shorter than that of the general population and varies further dependent on underlying diagnosis and age. For example, the median survival for a patient in Scotland aged 45 - 64 years starting RRT for glomerulonephritis is 7.7 years, whereas the median survival of a patient in the same age group with a diagnosis of diabetic nephropathy is 2.9 years. The life expectancy of a male of the same age group within the general Scottish population is 24.2 years. Instituting RRT prolongs life and reduces the incidence of vasculo-occlusive events in patients with ESRD. As such, patients with CKD should be monitored by a nephrologist in order that timely referral for preparation for RRT can be made.