Chronic kidney disease

Chronic kidney disease is particularly prevalent in older people. In many cases it is a consequence of diabetes and high blood pressure. The decrease in renal function does not cause any symptoms in the initial stages. Because of this, the condition often goes unnoticed until a very late stage. Specific treatments are available to slow down the deterioration of the kidneys.

At a glance

  • The kidneys clean the blood and affect many bodily functions. They are vital organs.
  • Chronic kidney disease is particularly prevalent in older people.
  • The decrease in renal function often goes unnoticed because there are no symptoms initially.
  • Most cases of chronic kidney disease in adults are caused by diabetes mellitus and high blood pressure.
  • More than two million people in Germany are estimated to be living with a permanently decreased renal function.
  • There are various treatments available that slow down further deterioration of the kidney in people who are already suffering from the disease.

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Chronic kidney disease: doctor and another man sitting at a table with a plastic anatomical model of a human torso. The doctor is pointing to the kidney on the model.

What is chronic kidney disease?

The kidneys are vital organs: they clean the blood and affect many bodily functions. Some conditions can temporarily reduce renal function. An enlarged prostate or kidney stones may cause a build-up of urine in the kidney. Circulatory failure temporarily reduces kidney performance.

A chronic kidney disease is diagnosed when the kidneys have not been working effectively for more than three months or have suffered permanent damage. The most common causes of the condition in adults are diabetes mellitus and high blood pressure.

Chronic kidney disease is particularly prevalent in older people. The condition often goes unnoticed for long periods because a decline in renal function does not initially cause any symptoms.

What are the signs of chronic kidney disease?

Chronic kidney disease is frequently only diagnosed when the kidney fails or health problems occur due to complications. Since the body does not eliminate sufficient water, waste products of metabolism slowly accumulate, leading to symptoms.

Symptoms may present all over the body, for example:

  • swelling (edema), for instance of the legs or face
  • nausea, vomiting, diarrhea
  • loss of appetite, weight loss
  • pallor, itching
  • fatigue, apathy, debility
  • difficulties concentrating, confusion, impaired consciousness or even loss of consciousness
  • paralysis, muscle cramps
  • dyspnea (shortness of breath)

What causes chronic kidney disease?

Most cases of chronic kidney disease in adults are caused by diabetes mellitus and high blood pressure.

The kidneys may also suffer permanent damage if:

  • the renal tissue becomes inflamed.
  • medication, particularly painkillers, is taken over the long term.
  • kidney stones, tumors or scarring interfere with the flow of urine.
  • congenital kidney diseases are present, for example, polycystic kidney disease.

How common is chronic kidney disease?

More than two million people in Germany are estimated to be living with a permanently decreased renal function. Most are over 60 years old.

Around 90,000 people a year have to start dialysis because their kidneys are not working properly. Kidney transplants account for more than half of all organ transplants in Germany: over 2,000 donor kidneys are transplanted every year.

Around 10,000 people die from complications of chronic kidney disease a year in Germany.

Chronische Nierenerkrankung: Jährlich müssen um die 90.000 Menschen zur Dialyse, weil ihre Nieren nicht mehr ausreichend funktionieren.

How does chronic kidney disease progress?

Although renal function is already impaired at the early stage of the disease, the kidneys can still purify the blood sufficiently well. This may continue to be the case for years, and the kidneys sometimes even heal themselves.

However it may also happen that renal function steadily deteriorates, ending in renal insufficiency. This may progress to complete (terminal) renal failure, which is life-threatening.

What can be done to reduce the risk of chronic kidney disease?

Chronic kidney disease can be caused by diabetes mellitus and high blood pressure. Therefore, it is a good idea to reduce the risk of developing these conditions. The most important steps in this regard are to avoid putting on excess weight and to get enough exercise.

People who already have diabetes or high blood pressure will often require additional medication. The goal is to achieve the right blood sugar and blood pressure levels and prevent complications such as kidney disease as far as possible.

How is chronic kidney disease diagnosed?

Doctors can diagnose the causes and severity of a chronic kidney disease by:

  • a detailed medical history (anamnesis).
  • a physical examination including blood pressure reading.
  • an ultrasound scan of the abdominal cavity and kidneys.
  • blood tests: for example, to measure creatinine, blood sugar, hemoglobin levels, or blood gas analysis to measure the acid-base balance.
  • a urine test, including a protein assay.

Results from these and other laboratory blood tests shed light on renal function. Doctors can use other results to find out, for example, whether the kidney disease has already caused complications, or whether diabetes mellitus is the cause.

If they are still not sure, scans such as computed tomography (CT) or a kidney biopsy (where a sample of tissue is taken from the kidney) may be advisable.

Is screening for chronic kidney disease possible?

People with diabetes mellitus or high blood pressure are at a higher risk of chronic kidney disease. People who are at a higher risk should have their kidneys examined regularly by their doctor. This allows renal insufficiency to be detected at the early stages. 

Under the Check-up 35 program, anyone over 35 covered by statutory health insurance are entitled to a free screening checkup every three years. The goal of the checkup is to detect signs of cardiovascular disease, diabetes and kidney disease at an early stage.

How is chronic kidney disease treated?

The progression of the disease can be halted or slowed down if the kidneys are still working more or less normally. This is mainly achieved through medication to lower the blood pressure and prevent cardiovascular disease. It is important for people with diabetes to check their blood sugar levels.

Other medication can help with complications such as anemia or metabolic bone disease, for example products containing iron, agents stimulating blood formation (erythropoiesis) or phosphate binders. Bicarbonate of soda is used to restore the acid/base balance.

It is also important for those affected to adapt their dietary habits to the stage of the kidney disease, control the amount they drink and exercise.

Dialysis or a kidney transplant are options for treating terminal renal failure. At least one of these treatments will usually be used, although some people consciously decide not to avail of either option. Palliative treatment is advisable when it is clear that a person will die soon. It helps to achieve an end of life that is as free of suffering as possible.

More detailed information on dialysis can be found at

Detailed information on kidney transplants is available on the website of the Federal Centre for Health Education (BZgA).

What rehabilitation programs are there for chronic kidney disease?

Chronic kidney disease affects people’s everyday lives. Those affected have to follow specific advice, particularly in relation to eating and drinking. Specialist dietary advice is usually accessible to those with renal problems and their family members. Many renal specialists offer this type of advice.

Patients receiving dialysis should normally ensure they do not drink too much. Since the kidneys cannot operate at full capacity they frequently eliminate almost no water, causing water retention. Sucking on a lemon segment, chewing sugar-free gum or a sour sweet can help alleviate thirst.

It is also helpful to:

  • avoid rooms where the air is dry,
  • drink slowly,
  • use small glasses and cups, and
  • take medication, wherever possible, with meals instead of an extra glass of water.

People with chronic kidney disease will usually have to take several medications permanently. A medication schedule can help people to remember when to take the medication.

However there are some medicines that people should not take because their renal function is impaired, such as ibuprofen for pain. They should discuss alternatives with their doctor. Many people have to get used to entirely new treatments such as insulin injections for diabetes.

What’s everyday life like with chronic kidney disease?

Living with a chronic kidney disease can be stressful. There are restrictions on people’s diet and on how much they can drink when taking medication. Dialysis also has a huge impact on work and private life as it is so time-consuming.

A freephone hotline for anyone with questions on how to cope with the condition is provided by the Association of German Kidney Centers and the Federal Kidney Association.

The prospect of most likely having to have treatment for the rest of one’s life and the restrictions this imposes, for family members as well, can be psychologically stressful and depressing. It can therefore be very helpful to talk about it with other people suffering from the same condition, either in a self-help group or during dialysis. Psychotherapy can help with severe or prolonged periods of psychological stress.

In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen – IQWiG).

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