What is Chronic Kidney Disease?

Chronic kidney disease (CKD) is a progressive loss in kidney function over a period of months or years. Each of your kidneys has about a million tiny filters, called nephrons. If nephrons are damaged, they stop working. For a while, healthy nephrons can take on the extra work. But if the damage continues, more and more nephrons shut down. After a certain point, the nephrons that are left cannot filter your blood well enough to keep you healthy.

When kidney function falls below a certain point, it is called kidney failure. Kidney failure affects your whole body, and can make you feel very ill. Untreated kidney failure can be life-threatening.

What you should not forget:

1. Early chronic kidney disease has no signs or symptoms.

2. Chronic kidney disease usually does not go away.

3. Kidney disease can be treated. The earlier you know you have it, the better your chances of receiving effective treatment.

4. Blood and urine tests are used to check for kidney disease.

5. Kidney disease can progress to kidney failure.

Kidney Diseases are Common, Harmful and often Treatable

Common: Between 8 and 10% of the adult population have some form of kidney damage, and every year millions die prematurely of complications related to Chronic Kidney Diseases (CKD).

Harmful: The first consequence of undetected CKD is the risk of developing progressive loss of kidney function that can lead to kidney failure (also called end-stage renal disease, ESRD) which means regular dialysis treatment or a kidney transplant is needed to survive.

The second consequence of CKD is that it increases the risk of premature death from associated cardiovascular disease (i.e. heart attacks and strokes). Individuals who appear to be healthy who are then found to have CKD have an increased risk of dying prematurely from cardiovascular disease regardless of whether they ever develop kidney failure.

Treatable: If CKD is detected early and managed appropriately, the deterioration in kidney function can be slowed or even stopped, and the risk of associated cardiovascular complications can be reduced.

How is kidney function measured?

The main indicator of kidney function is your blood level of creatinine, a waste product of the body produced by muscles and excreted by the kidneys. If kidney function is reduced, creatinine accumulates in the blood leading to an elevated level when a blood test is checked.

Kidney function is best measured by an indicator called GFR (Glomerular Filtration Rate) which measures the blood filtration rate by kidneys. This indicator allows doctors to determine if the kidney function is normal, and if not, to what level the reduced kidney function has deteriorated. In everyday practice, GFR can easily be estimated (eGFR), from measurement of the blood creatinine level, and taking into account, age, ethnicity and gender..

Causes of CKD

High blood pressure (hypertension) and diabetes are the most common causes of kidney disease. The high blood pressure causes just over a quarter of all cases of kidney failure. Diabetes has been established as the cause of around one-third of all cases and is the commonest cause of ESRD in most developed countries.

Other less common conditions include inflammation (glomerulonephritis) or infections (pyelonephritis). Sometimes CKD is inherited (such as polycystic disease) or the result of longstanding blockage to the urinary system (such as enlarged prostate or kidney stones).

Some drugs can cause CKD, especially some pain-killing drugs (analgesics) if taken over a long time. Often doctors cannot determine what caused the problem.

Symptoms

A person can lose up to 90% of their kidney functions before experiencing any symptoms.A person can lose up to 90% of their kidney functions before experiencing any symptoms.

Most people have no symptoms until CKD is advanced. Signs of advancing CKD include swollen ankles, fatigue, difficulty concentrating, decreased appetite, blood in the urine and foamy urine.

Detection

The majority of individuals with early stages of CKD go undiagnosed. On WKD we are calling on everyone to check if they are at risk for kidney disease and encouraging people with any risk factors to take a simple kidney function test.

Kidney disease usually progresses silently, often destroying most of the kidney function before causing any symptoms. The early detection of failing kidney function is crucial because it allows suitable treatment before kidney damage or deterioration manifests itself through other complications.

Simple laboratory tests are done on small samples of blood (to measure creatinine content and estimate GFR) and on urine (to measure creatinine and albumin excretion).

Your doctor uses the results of your Serum Creatinine measured in the blood to estimate your overall kidney function, or Glomerular Filtration Rate (GFR) and your blood sugar to be sure you do not have diabetes. A simple dipstick test may be used to detect excess protein in the urine.

Serum Creatinine: Creatinine is a waste product in your blood that comes from muscle activity. It is normally removed from your blood by your kidneys, but when kidney function slows down, the creatinine level rises. Your doctor can use the results of your serum creatinine test to calculate your kidney function, or GFR.

Glomerular Filtration Rate (GFR): Your GFR tells how much total kidney function you have. It may be estimated from your blood level of creatinine. Normal is about 100 ml/min, so lower values indicate the percentage of normal kidney function which you have. If your GFR falls below 60 ml/min you will usually need to see a kidney disease specialist (called a nephrologist), If the treatment you receive from the nephrologist does not prevent a further reduction in GFR, your nephrologist will speak to you about treatments for kidney failure like dialysis or kidney transplant. A GFR below 15 indicates that you may need to start one of these treatments soon.

Urine albumin. The presence of excess protein in the urine is also a marker of CKD and is a better indicator of the risk for progression and for premature heart attacks and strokes than GFR alone. Excess protein in the urine can be screened for by placing a small plastic strip embedded with chemicals that change color when protein is present (urine dipstick) into a fresh urine specimen or can be measured more accurately with a laboratory test on the urine.

CKD in elderly people

About 1 in 10 people have some degree of CKD. It can develop at any age and various conditions can lead to CKD. It however becomes more common with increasing age. After the age of 40, kidney filtration begins to fall by approximately 1% per year. On top of the natural aging of the kidneys, many conditions which damage the kidneys are more common in older people including diabetes, high blood pressure and heart disease.

It is estimated that about one in five men and one in four women between the ages of 65 and 74, and half of people aged 75 or more have CKD. In short, the older you get the more likely you are to have some degree of kidney disease. This is important because CKD increases the risk of heart attack and stroke, and in some cases can progress to kidney failure requiring dialysis or transplantation. Regardless of your age, simple treatments can slow the progression of kidney disease, prevent complications and improve quality of life.