What's your risk of kidney failure - and how can you reduce it?

Chronic kidney disease (CKD) is common, affecting an estimated 14% of people in Canada and USA. Diabetes and hypertension (high blood pressure) are responsible for about 60% of cases of CKD.

Unfortunately, kidney disease is often not detected until it has progressed to an advanced stage. One reason is because earlier stages don’t usually have any symptoms. By the time a person has symptoms of kidney disease, it is usually at stage 4 or 5 (see below).

These late-stage symptoms can include:

swelling in ankles
decreased mental sharpness
feeling itchy
muscle twitches and cramps
fatigue and weakness
loss of appetite
nausea and vomiting
urinating less

Screening for CKD should be done with BOTH a blood test to measure kidney function (called glomerular filtration rate or GFR, which is calculated from a blood test called creatinine), AND a urine test to check for protein (called urine albumin:creatinine ratio or ACR).

Even if GFR is normal, a persistent elevation in ACR also counts as having CKD. While blood testing for GFR is pretty routine, ACR isn’t checked often enough; this is another reason why CKD often goes undetected.

Chronic kidney disease (CKD) is divided into 5 stages.

Stage 1 (GFR >90): none or slight
Stage 2 (GFR 60-89): mild
Stage 3 (GFR 30-59): moderate
Stage 4 (GFR 15-29): severe
Stage 5 (GFR <15): approaching failure

Think of GFR like percentage function. In other words, a person with a GFR of 42 has about 42% of normal kidney function.

I highly recommend this excellent kidney failure risk equation calculator , for you and/or your health care provider. This is an evidence-based tool, designed by Dr Navdeep Tangri and colleagues, and supported by the Can-SOLVE Chronic Kidney Disease network.

This calculator takes all of 10 seconds to run. All you need to know is your (or your patient’s) GFR and urine albumin:creatinine ratio (with the units of measure, selected from the drop down menu), and the calculator will tell you:

your stage of kidney disease (stage 1-5)
your risk of progressing to kidney failure (requiring dialysis or transplant) in the next 2 years
your risk of progressing to kidney failure in the next 5 years
how much good blood pressure control can reduce your risk
how much an ACE inhibitor (pril) or ARB (sartan) can reduce your risk
how much an SGLT2 inhibitor (gliflozin) can reduce your risk (if appropriate to consider, based on your GFR)

There is also a fantastic handbook for people with stage 3-5 chronic kidney disease, including: