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Understanding Chronic Kidney Disease (CKD)

What Is Chronic Kidney Disease?

Chronic kidney disease (CKD), also known as chronic renal disease, is a condition that occurs when your kidneys don’t work as well as they should to excrete waste, toxins, and excess fluid from your body.

CKD is characterized by a progressive loss of kidney function over time.

The end stage kidney disease (ESKD), end stage renal disease (ESRD), or kidney failure may develop over many years or within only a few months. At this stage, you will require either dialysis or a kidney transplant.

A female pharmacist sits with a senior female patient in the pharmacist consultation area and discusses her prescription and choice of medication. She is holding an a strip of the pills and chatting to the customer .In the background a female pharmacy assistant is checking orders at the counter .

An estimated 8 to 16% of people globally are diagnosed with CKD

Often undetected in early stages due to missing symptoms

Up to 90% remain undiagnosed until very late

Living with Chronic Kidney Disease

Chronic kidney disease is a progressive disease and there comes a point when the kidneys cannot fulfill their task any longer and dialysis or transplantation become necessary. But you are not helpless, there is a lot you can do to slow the progression of the disease before the need for dialysis, for example, by adopting a conservative treatment approach. This approach uses lifestyle interventions and medications and the earlier you start, the better. Diet changes, particularly the reduction of protein intake (low or very low protein diet), are an important part of this conservative CKD treatment.

Explore conservative treatments to slow CKD progression early

Be Inspired by Real Stories from People Living with CKD

Learn about chronic kidney disease (CKD), its symptoms, stages, and treatment. Hear real patient stories and find out how to manage CKD and live well.
Understanding Chronic Kidney Disease (CKD)
Understanding Chronic Kidney Disease (CKD)
Learn about chronic kidney disease (CKD), its symptoms, stages, and treatment. Hear real patient stories and find out how to manage CKD and live well.
Understanding Chronic Kidney Disease (CKD)
Understanding Chronic Kidney Disease (CKD)
Learn about chronic kidney disease (CKD), its symptoms, stages, and treatment. Hear real patient stories and find out how to manage CKD and live well.
Understanding Chronic Kidney Disease (CKD)
Understanding Chronic Kidney Disease (CKD)
Discover more inspiring stories of managing CKD through lifestyle changes

The Kidneys

The kidneys are two bean-shaped organs. They are located near the middle of your back, just below the rib cage. The kidney contains approximately one million functional units called nephrons. The nephrons filter blood, reabsorb and secrete substances to generate urine. But this is just 1 out of the 5 important main tasks the kidneys perform day in and day out relentlessly.

Role of the Kidneys

The main purposes of the kidney can be defined by the following five pillars:

Remove wastes 

Your kidneys act like a filter and remove wastes and extra fluid from your body.

Control blood pressure

The kidneys need pressure to work properly. They can increase it if needed or lower it by controlling fluid levels. And they can produce a hormone that causes blood vessels to constrict.

Make red blood cells

Your kidneys make a hormone called erythropoietin. Erythropoietin then tells the bone marrow to make red blood cells.

Keep bones healthy

The kidneys make an active form of vitamin D, which is needed to absorb calcium and phosphorus, both important minerals for making bones strong. The kidneys also balance calcium and phosphorus in the body.

Control pH Levels 

pH is a measure of acid and base. The kidneys balance the chemicals that control acid levels in your body.

Sources: https://www.niddk.nih.gov/health-information/kidney-disease/kidneys-how-they-work (Accessed 02.05.2025)

Kidney Function Explained

The kidneys filter around 1.2 liters of blood per minute, processing roughly 1,700 liters daily. Blood enters through the renal arteries, travels through smaller vessels, and reaches the glomerular capillaries. These capillaries filter blood and primary urine is created containing water, salts, sugar, and waste.

About 170 liters of primary urine are filtered each day, but only 1.7 liters of urine are finally excreted. When the primary urine travels through the tubule, most components are reabsorbed based on the body's needs. The remaining urine moves to the collecting tubule, then to the calyces of the kidney, and finally to the renal pelvis.

Finally it is transported through the ureter to the bladder for storage and is then excreted via the urethra.

Sources: https://www.ncbi.nlm.nih.gov/books/NBK279384/ (Accessed 02.05.2025); National Institute of Diabetes and Digestive and Kidney Diseases. National Institutes of Health https://www.niddk.nih.gov/health- information/kidney-disease/kidneys-how-they-work (Accessed 02.05.25)

How is Kidney Function Measured?

Your healthcare team may talk about the work your kidneys do as “renal function” or “kidney function”. If you have two healthy kidneys, you have 100 percent of your kidney function which is more than you really need. Some people are born with only one kidney and are still able to live a normal and healthy life. Many people donate one kidney for transplantation to a family member or friend and continue to have a relatively normal kidney function. Symptoms usually only appear when the kidney function has considerably declined. Small declines, however, do not necessarily cause a problem. 

One common measure of kidney function is the glomerular filtration rate (GFR). It describes how many milliliters of blood the kidneys can filter per minute. The normal value is 90 ml/min or higher. Chronic kidney disease is defined to start at a GFR level below 60ml/min, but many people feel no symptoms until the kidney function has dropped to a level of <30ml/min.

Often you will see GFR values with the unit ml/min/1.73 m², because technically, GFR is expressed in relation to body surface area, which averages 1.73 m². 

Stages of CKD and corresponding GFR values

What Causes Chronic Kidney Disease and Who is at Risk?

Chronic Kidney Disease usually develops due to other health conditions or lifestyle factors that put pressure on the kidneys. Even though CKD becomes more common with increasing age, you can develop it at any age. In any case, controlling those risk factors and scheduling regular check-ups with your healthcare provider is a good start to keep your kidneys healthy.

The most common risk factors include:

  • Suffering from diabetes or obesity
  • Having high blood pressure
  • Other family members with CKD
  • Being over 60 years old
  • Lifestyle factors like smoking

Symptoms of Chronic Kidney Disease

One of the biggest challenges with Chronic Kidney Disease is that early symptoms can be subtle, unspecific, or missing entirely. Early symptoms of kidney disease may include:

  • Feeling tired or having low energy
  • Swelling in feet or ankles
  • Puffiness around the eyes, especially in the mornings
  • Changes in urination (color, frequency, or foaming)
  • Trouble concentrating or “brain fog”
  • Itching, dry skin
  • Poor appetite
  • Trouble sleeping
  • Muscle cramps at night

If you're experiencing several of these symptoms, talk to your doctor about kidney function testing.

How Is CKD Diagnosed?

Since a person can have kidney disease without any symptoms, your doctor may initially detect the condition through routine blood and urine tests. Testing is the only way to know if you have CKD. This is why it is important to do regular health checks, especially if you have one or more risk factors for developing the disease. 

Urine test

This test checks the levels of proteins in your urine. Proteins should ususally not appear in the urine and are therefore a marker of kidney damage. If this tet is repeatedly "positive" for protein ver a period of three months or more, it is usually a sign of kidney disease.

Blood test

The main test for kidney disease measures the levels of creatinine in your blood. Your physician uses your blood test results, along with other parameters like your age, size, gender and other factors, to calculate how many milliliters of fluid your kidneys are able to filter per minute. 

This calculation is known as your estimated glomerular filtration rate (eGFR).

 

Managing CKD: What You Can Do

There is no cure for chronic kidney disease, but there is a lot you can do to slow it down and live well. Treatment of CKD varies according to the severity of the disease, but steps can be taken in all cases to: control hypertension, correct salt and water imbalance, treat urinary tract infections, and reduce the risk of heart and blood vessel diseases. Additionally, you can slow it down by lifestyle changes - including adapted nutrition - along with regular check-ups and medication intake.

Personalized treatment options include conservative therapy and renal replacement therapies such as dialysis or kidney transplantation. 

General practitioner and her aged patient talking about kidney diseases

Conservative treatment of CKD

A comprehensive conservative treatment of chronic kidney disease (CKD) uses dietary interventions and medications from earlier stages of the disease until the start of dialysis. 

Dietary interventions, particularly the reduction of protein intake (low/very low protein diet), are an important part of conservative CKD treatment. 

Depending on the severity of protein reduction, a supplementation with keto-analogues might be indicated. Clinical studies have shown that this combination may postpone the start of dialysis.

Nurse showing medicines to senior woman who is sitting in a wheelchair at dining table.

Proteins are important for various functions in your body, including build-up of muscles and cells for the immune system. Eating the right amount of protein is therefore especially important for CKD patients. Over-consumption of protein, when your kidneys are weak, will lead to an accumulation of nitrogen-containing waste in your body. This can have harmful consequences such as: nausea, weakness, tiredness, shortness of breath and reduced appetite.

But too little protein can lead to a dangerous weakening of the body. This is when a supplementaion with keto-analogues might be indicated. 

Keto-analogues supplementation to your reduced protein diet increases the quality of the protein intake. They are nitrogen-free precursors of essential amino acids. Keto-analogues are converted to the respective amino acids in the body. In this way, no additional nitrogen intake occurs, and the formation of nitrogen-containing waste products is reduced.

It is important to mention that keto-analogues do not work on their own; they are essential supplements to a protein reduced diet.

Early treatment of advanced CKD patients with keto-analogue may delay the start of dialysis. Keto-analogue supplementation is a safe and effective way for patients on a protein-reduced diet to ensure a sufficient daily intake of essential amino acids.

Nutrition is an important element in the management of chronic kidney disease. As you must pay attention to several ingredients when changing your nutrition to a ‘kidney diet’, it is recommended that you receive training from a specialized dietitian. Please ask your doctor about your individual nutrition requirements and about instructions from a dietitian.

In general, for pre-dialysis stages, it is recommended that your intake (or “kidney diet”) consists of:

  • Low amounts of protein
  • Sufficient calories
  • Low amounts of table salt (i.e. sodium)
  • Low amounts of phosphate
  • Low amounts of potassium
  • Variable amounts of calcium (depending on your individual needs, considering all different sources of calcium)

Treatment for Kidney Failure

If CKD progresses to kidney failure or stage 5, treatment options include:

Dialysis

When the kidneys can no longer clean your blood sufficiently, dialysis is needed to take that job. There are different forms of dialysis possible:

  • Hemodialysis uses a machine to clean your blood
  • Peritoneal dialysis uses the lining of your abdomen to filter your blood

Kidney Transplant

Also a kidney transplantation might be an option under certain circumstances. Even though it may offer the best quality of life, though it requires a donor and lifelong medication to prevent rejection.

Man, doctor and dialysis machine in hospital for kidney assessment, organ fail and medical diagnosis for health. Patient, woman and screen exam for Nephrology, filter blood and hemodialysis treatment.