Chronic Kidney Disease (CKD)

Chronic kidney disease (CKD) is when the kidneys stop working as well as they should. When they are working normally, the kidneys filter the blood and remove waste and excess salt and water. These wastes and fluids are combined to form urine.

In people with CKD, the kidneys slowly lose the ability to filter the blood. In time, the kidneys can stop working completely. That is why it is so important to keep CKD from getting worse.

In the early stages of CKD, there are no symptoms. The disease can progress to complete kidney failure, also called end-stage kidney disease. This occurs when kidney function has worsened to the point that dialysis is required to maintain good health and even life, which is typically when kidney function is approximately 10 percent or less of the normal kidney function.

Filtering of the blood is done in the kidney by structures called "nephrons". The nephron, including the glomeruli and the tubules, must be healthy, and the path from the nephron to the draining tubes must not be blocked. There are normally approximately one million filtering units or nephrons in each kidney. Diseases (diabetes and high blood pressure) that reduce the number of normally functioning nephrons and/or reduce the function of nephrons cause CKD over time.

The main goal of treatment is to prevent progression of CKD to complete kidney failure. The best way to do this is to diagnose CKD early and control the underlying cause.

Physician may use several tests to diagnose CKD. These include the following:

1- Glomerular Filtration Rate (GFR) — The glomerular filtration rate (GFR) gives an approximate measure of the overall filtering abilities of the kidneys. The GFR level is often shown on routine blood chemistry lab reports that your doctor obtains, and it is used for monitoring of kidney function impairment. 

The GFR is an approximate measure of the volume of blood that is filtered/cleaned by your kidneys per minute. 

The normal value for GFR depends upon age, sex, and body size, and is approximately 100 mL/min in healthy, young individuals. As we age, the kidneys lose some of their filtering capabilities. 

GFR less than 60 mL/min for 6 months is considered CKD.

 2- Urine tests — The presence of albumin or protein in the urine is a marker of kidney disease. Even small amounts of albumin in the urine may be an early sign of CKD in some people, particularly those with diabetes and high blood pressure. 

3- Imaging studies — Imaging tests (such as kidney ultrasound) is recommended to determine if there are any obstructions (blockages) of the urinary tract, kidney stones, or other abnormalities, such as many large cysts seen in a genetic disease called polycystic kidney disease. Kidney ultrasound is very useful in evaluating the chronicity of kidney disease which can guide medical management. We will elaborate more on the usefulness and utility of kidney ultrasound in future blogs!

Urine testing and kidney ultrasounds are underutilized. It is important for any patient with abnormal GFR to be fully evaluated with urine studies and renal ultrasound, to get a full picture of what may be causing the decreased GFR. The sooner we can find an abnormality, the better chance we have of correcting it and/or preventing progression to more advanced disease.