Brief overview
- Symptoms: Usually no early symptoms, later including fluid retention due to reduced urine output, high blood pressure and gastrointestinal complaints
- Causes and risk factors: Various diseases, especially diabetes mellitus and hypertension, but also certain drugs
- Diagnosis: On the basis of various blood and urine values, in some cases imaging procedures such as ultrasound or a tissue biopsy
- Treatment: The main focus is on treating the underlying disease that causes the kidney damage
- Course and prognosis: The disease usually progresses slowly over years or even decades. Many sufferers require dialysis or kidney transplantation at some point.
- Prevention: Chronic renal failure can best be prevented by optimally treating potentially triggering diseases, such as diabetes.
What is chronic renal failure?
In Europe, about 13 to 14 out of 100,000 people per year develop chronic renal failure. The risk of developing the disease increases with age. Chronic renal insufficiency has various, possibly dangerous effects on the body. If left untreated, the disease can lead to kidney failure and ultimately death in extreme cases.
Consequences for the body
Each kidney consists of more than one million renal corpuscles (glomeruli). These small, spherical structures contain a tangle of tiny veins whose walls have a filtering structure. Through these filter vessels, the kidneys rid the blood of various metabolic products that the body no longer needs. Physicians refer to such substances as urinary substances.
Chronic kidney failure makes it impossible to adequately filter and cleanse the blood because, due to various diseases, some of the renal corpuscles perish. If too many renal corpuscles are damaged as the disease progresses, the kidneys are no longer able to completely eliminate the toxic metabolic products – they collect in the blood and cause urine poisoning (uremia).
In addition to its excretory function, the kidney has other tasks. It helps to control blood pressure, bone metabolism, blood salts (electrolytes) and the acid-base balance. It also produces various hormones that are important for blood formation, among other things. Thus, chronic renal insufficiency affects other important bodily functions.
Severity of chronic renal failure
Depending on the severity of chronic renal failure, doctors distinguish between five different disease stages. The glomerular filtration rate (GFR) is the decisive factor. It is a measure of the amount of blood that the kidneys filter in a given time. In chronic kidney disease, the GFR is reduced to varying degrees depending on the severity of the disease.
You can read more about this in the article Kidney failure stages.
What are the symptoms of chronic renal failure?
Chronic renal failure often does not cause clear symptoms until the later stages of the disease, when kidney function is already severely impaired.
You can read about the symptoms of chronic renal failure in the article Renal failure symptoms.
The most common causes of renal corpuscle damage in chronic renal failure are:
- Diabetes mellitus: In about 35 percent of all cases, chronic renal failure is caused by diabetes.
- High blood pressure (hypertension): On the one hand, it is an important cause of chronic kidney failure because it damages the renal corpuscles. On the other hand, it is also a consequence, since hormones that increase blood pressure are produced more frequently as kidney function declines.
- Kidney inflammation: Both inflammation of the renal corpuscles (glomerulonephritis) and inflammation of the urinary tubules and the space surrounding them (interstitial nephritis) result in chronic renal failure in some cases.
- Cystic kidneys: In this congenital malformation, numerous fluid-filled cavities occur in the kidneys, severely limiting their function.
- Medications: Kidney-damaging drugs include over-the-counter painkillers such as paracetamol, ibuprofen or diclofenac. Particularly with prolonged use, they may cause chronic renal insufficiency.
In addition to these causes, there are numerous risk factors. Although they do not trigger the disease directly, they increase the likelihood of chronic renal failure. These include, for example
- older age
- male gender
- Detection of proteins in the urine
- obesity
- nicotine consumption
Examinations and diagnosis
In a detailed discussion with the patient, the physician first takes the patient’s medical history. Among other things, he asks about existing kidney damage, chronic diseases, the use of medication and kidney diseases in the family. This is followed by a physical examination with measurement of blood pressure and heart rate.
Blood and urine test
If the patient also excretes protein in the urine, this confirms the suspicion of kidney weakness. With the help of another laboratory value, the glomerular filtration rate (GFR), the doctor determines the severity of the disease.
Further examinations
Once the diagnosis of “chronic kidney failure” has been established, the search for the causes begins. Depending on the suspected diagnosis, doctors perform further urine and blood tests as well as imaging examinations such as ultrasound (sonography). Sometimes it is necessary to take a tissue sample from the kidney (kidney biopsy). The examinations also look for possible secondary diseases of kidney weakness, for example anemia (renal anemia).
Treatment
The treatment of chronic renal failure depends on its causes and severity. The aim is to eliminate the cause if possible, or at least to control it as well as possible so that chronic kidney weakness does not progress further. However, kidney tissue that has already been destroyed cannot be restored.
- Abundant fluid intake (two to two and a half liters) and use of diuretic medications.
- Regular control of blood salts (electrolytes) and body weight
- Treatment of hypertension with drugs (especially ACE inhibitors and AT1 blockers)
- Medication to reduce proteinuria, i.e. the excretion of proteins in the urine
- Taking medications that lower blood lipid levels (lipid-lowering drugs)
- Treatment of anemia caused by kidney weakness (renal anemia)
- Treatment of bone disease (vitamin D deficiency due to renal insufficiency)
- Avoidance of medications that damage the kidneys
- Proper diet
Despite treatment, chronic kidney failure continues to progress in many cases, eventually requiring artificial blood washing (dialysis) or, in the final stages, a kidney transplant.
Nutrition in chronic renal failure
Nutrition also has an influence on the course of chronic renal failure. You can read more about this in the article Nutrition in renal failure.
Course of the disease and prognosis
Chronic renal failure usually progresses more rapidly in men and seniors than in women and younger people. High blood sugar and blood pressure levels as well as obesity and smoking also have a negative effect on the course of the disease.
Chronic renal failure may shorten the life expectancy of those affected. This is particularly the case if diabetes mellitus is the cause of the kidney failure. Some sufferers die from the consequential damage caused by the diseased kidneys, for example from diseases of the cardiovascular system.
Prevention
The most common causes of chronic renal failure are diabetes mellitus and high blood pressure. Good control of blood sugar and blood pressure levels can therefore prevent chronic kidney failure.
