Diagnosis of Chronic Kidney Failure

Reading time: 1 min
Blood extraction tube

Chronic kidney disease or chronic kidney failure is diagnosed through blood tests that measure creatinine and urea, or BUN, levels as these are the main toxins eliminated by our kidneys. Urine is also analysed to discover the exact volume and composition of urinary output. These results are used to calculate the overall percentage of kidney function (glomerular filtration rate, GFR) which subsequently determines the degree of kidney failure.

stage description glomerular filtration rate (GFR)
1 Kidney damage with normal GF > 90 mL/min
2 Kidney damage with mild loss of GF 60–89 mL/min
3 Moderate loss of GF 30–59 mL/min
4 Severe loss of GF 15–29 mL/min
5 Kidney failure < 15 mL/min or dialysis


Magnetic resonance

Additionally, an ultrasound is taken and, in some cases, a CT scan or MRI to determine the kidneys’ size and shape. In other instances, a kidney biopsy may also be carried out.

It is essential to diagnose kidney disease in its early stages (1 to 3) in order to prevent the loss of kidney function and onset of cardiovascular complications, thus preserving function for several years and delaying the need to resort to dialysis. Most individuals do not notice any particular symptoms; they may feel a little tired or have swollen legs.

It is important to follow the nephrologist’s indications when first diagnosed with kidney disease so as to reduce the rate of kidney function deterioration, e.g., reduce salt intake, lose weight or follow an appropriate diet, amongst others.

Substantiated information by:

Marta Quintela
Manel Vera
Ángeles Mayordomo
María Teresa López
Bárbara Romano Andrioni
Anna Yuguero
Montserrat Monereo

Published: 20 February 2018
Updated: 20 February 2018


Receive the latest updates related to this content.

Thank you for subscribing!

We have received your information. Check your inbox, in a few moments you will receive a confirmation email.

An error occurred and we were unable to send your data, please try again later.