Renal Cyst (Cystic Kidneys)

A renal cyst is a fluid-filled cavity in or on the kidney. If several cysts form, one speaks of a cystic kidney. Isolated renal cysts form sporadically (accidentally), whereas the cystic kidney is hereditary.

Renal Cyst (Cystic Kidneys)

What is a kidney cyst?

A renal cyst is a sac-like or blister-like growth inside or around the kidney. The outside of the kidney cyst consists of smooth skin, inside there is a cavity filled with fluid. See etaizhou for What does Microphthalmos Mean.

If such cysts only occur sporadically, they are harmless and do not cause any symptoms. On the other hand, if several cysts form within the kidney, which is known as a cystic kidney, the function of the kidney can be impaired. A cystic kidney causes various symptoms and can lead to kidney failure. They are usually hereditary and are among the most common hereditary diseases.

A single renal cyst is also a common renal malformation. Children are rarely affected, but the likelihood of a kidney cyst forming increases with age.


Isolated renal cysts often form without any apparent cause. This is known as idiopathic origin. The cystic kidney, on the other hand, is hereditary in most cases. There is a gene mutation on chromosome no. 16, more rarely on chromosome no. 4.

A distinction is made between autosomal dominant and autosomal recessive inheritance. Both occur in the cystic kidney. In autosomal dominant inheritance, the disease is passed on to the child even if only one parent passes on the mutated gene.

In autosomal recessive inheritance, the cystic kidney only develops in the offspring if both parents are carriers of the defective gene. This means that even if one parent passes on the genetic defect, the child will not develop the disease because the healthy gene from the other parent can completely take over its job.

However, cystic kidneys can also develop as a result of long-term dialysis. Dialysis is a blood purification procedure that takes over the work of sick or weak kidneys.

Symptoms, Ailments & Signs

If the kidney cysts occur individually, they usually do not develop any symptoms or symptoms. The growths often go unnoticed for many years. Larger cysts are expressed by pain in the kidney area. Swelling and blood in the urine may also occur as the disease progresses. Cystic kidneys always cause symptoms in the long term.

Damage to the kidney tissue can lead to high blood pressure and urinary tract infections. Then there is increased blood in the urine or severe flank pain that can radiate to the back and abdomen. The pain rarely extends to the hips and lower back. The symptoms already lead to chronic kidney failure in childhood.

This manifests itself in acute pain, digestive problems and an increasing feeling of illness. Many patients suffer from exhaustion and a reduction in mental and physical performance. If it is a medullary sponge kidney, there will be no symptoms for a long time. The disease then often only manifests itself years later, when the disturbed coagulation leads to the formation of urinary stones.

This is followed by symptoms such as colic and kidney pain. The signs of the disease take a gradual course and, in extreme cases, lead to kidney failure. If the kidney cysts or cystic kidneys are treated surgically and with medication at an early stage, the symptoms disappear almost completely.

Diagnosis & History

Individual kidney cysts usually do not cause any symptoms and often remain undetected. They are usually only discovered by chance during an ultrasound examination (sonography), a CT (computed tomography) scan or an X-ray examination.

In rare cases, the kidney cyst becomes inflamed. Such an infection can cause various symptoms, such as blood in the urine, pain in the lower side of the back, and inflammation of the kidneys and urinary tract.

In a cystic kidney, the kidney enlarges over time and there are repeated urinary tract infections with blood in the urine. Patients suffer from pain in the kidney area, they feel less efficient and often have high blood pressure. In the autosomal dominant inherited cystic kidney, the cyst formation often spreads to other organs such as the lungs, spleen or liver.

Heart valve defects sometimes occur with this disease. In autosomal recessive inheritance, the symptoms appear in early childhood and lead to early kidney failure. If cystic kidneys are suspected based on the symptoms, imaging methods (ultrasound, X-ray, CT) are used, as well as blood tests and a kidney examination (renoscopy).


Simple kidney cysts usually do not require treatment. They often cause no symptoms and are harmless. However, kidney cysts from a size of ten centimeters can cause abdominal and back pain, renal colic and digestive problems. Cysts can also become inflamed and lead to the formation of abscesses. Cracks or bleeding can also occur in the cysts. These can cause significant pain.

In such cases, surgery may be necessary to relieve the pain. Cysts with a thick cell wall through which blood flows must also be removed in the course of an operation. Such renal cysts could contain portions of malignant tissue. Malignant kidney tumors could subsequently develop from these degenerated cysts.

If cysts occur frequently and displace healthy kidney tissue in the course of this, this can be an indication of congenital and inherited cystic kidneys. This can cause serious complications. Those affected feel massive flank, back and abdominal pain. In addition, a reddish discoloration of the urine often occurs. Affected people are increasingly suffering from urinary tract infections such as kidney pelvis and bladder infections.

This inflammation is accompanied by painful urination and sometimes fever. The cysts also promote the formation of kidney stones and high blood pressure. The congenital cystic kidney can damage the kidney so much over the long term that it can only function to a limited extent. Those affected then have renal insufficiency, which can result in kidney failure.

When should you go to the doctor?

Kidney pain, blood in the urine, and high blood pressure indicate a kidney cyst. Such a growth must be diagnosed and treated promptly to prevent the development of further cysts. If there are other symptoms, such as recurring urinary tract infections or intestinal diverticula, the patient should speak to their family doctor immediately. People who have an unhealthy lifestyle and, for example, regularly consume alcohol or other drugs are at an increased risk of developing a kidney cyst. The use of certain medications as well as chemo or radiation treatments can also cause a kidney cyst under certain circumstances.

Affected persons should have the above symptoms clarified immediately. This is particularly necessary if the cyst has already caused severe discomfort. A kidney cyst can be diagnosed by a general practitioner. Treatment is carried out by various specialists such as nephrologists or gastroenterologists. Large growths must be removed in the hospital. In addition to symptomatic treatment, patients should consult a nutritionist and work out a diet together with them. Psychological triggers can be identified and treated as part of a psychological consultation.

Treatment & Therapy

A kidney cyst usually does not require treatment because it causes no symptoms. Only if the cyst is very large is it punctured. The tumor is pricked with a hollow needle and the liquid is sucked out. The substance is then examined in a laboratory for possible pathogens and their composition.

The cystic kidney cannot be treated curatively because the cause lies in the genes. Painkillers can be given to relieve pain. If the cysts are very large, a puncture will also provide relief and reduce pain. In the long run, however, the kidneys will no longer be able to fulfill their function due to the many cysts and the blood must be cleaned by dialysis.

There are two different procedures, hemodialysis (HD) and peritoneal dialysis (PD). In hemodialysis, which is used more frequently, the blood is cleaned outside the body using an artificial kidney and then returned to the body. In peritoneal dialysis, the blood inside the body is filtered through the patient’s peritoneum. However, dialysis cannot permanently replace kidney function and in most cases is only used as a temporary stopgap until a suitable organ for a kidney transplant is available.

Outlook & Forecast

The prognosis of a kidney cyst can be very different. Normally, no further medical care is necessary, since there are no symptoms and the cyst is harmless in appearance. It often remains undetected for a long period of time and then detaches itself over time. It is automatically removed from the body and does not require any further medical activities.

However, if kidney cysts are hereditary, they should be observed by a doctor and checked regularly. Here the risk of complications and the development of various complaints increases. Due to genetics, cysts in the kidney area repeatedly develop over the course of life. In the event of an unfavorable further development, these can lead to various complaints and health impairments. If the cyst grows in an unfavorable region, it is removed as quickly as possible with a minor surgical procedure.

A mutation of the existing renal cyst occurs in some patients. This is usually the case when the kidney cyst remains in the organism for several years. The prognosis is considerably worse with such a development. If left untreated, the malignant tissue change then leads to the development of kidney tumors. In an advanced stage of the disease, these can lead to the premature death of those affected. Therefore, they must be surgically removed at an early stage.


There is no prevention against kidney cysts. However, if cases of cystic kidneys are already known in the family, it is advisable to have genetic tests examined to determine whether a gene mutation is present.


In the case of a kidney cyst, the patient usually has no or only very few and limited direct follow-up measures available. For this reason, the patient should ideally consult a doctor at an early stage so that other complications or symptoms do not arise. Therefore, the focus of this disease is early detection and treatment.

As a rule, self-healing cannot occur, so that those affected are always dependent on medical treatment. The renal cyst can be alleviated relatively well by surgical intervention. In any case, the affected person should rest and rest after such an operation, whereby exertion or stressful and physical activities are to be avoided.

Regular checks and examinations by a doctor are also necessary after the procedure in order to identify further complaints at an early stage. In many cases, a healthy lifestyle with a balanced diet can also have a positive effect on the further course of this disease. Those affected should drink a lot. Whether the kidney cyst will lead to a reduced life expectancy of those affected cannot be predicted in general.

You can do that yourself

Patients suffering from kidney cysts should independently initiate measures to alleviate the symptoms in addition to medical and medical care. Good and healthy lifestyle habits help in the recovery process and can have a preventive effect later on.

It is particularly important to avoid alcohol, nicotine and drugs. These pollutants and toxins have a negative effect on kidney activity and further worsen the general state of health. Consuming enough liquid is important so that pathogens and dead tissue cells can be removed from the body. The recommended minimum amount is usually two liters of liquid per day. The consumption of natural fruit juices or non-carbonated water is advisable. Eating fresh fruit and vegetables is good for building up the body’s defenses and stabilizing the immune systemalso highly recommended. Sufficient physical exercise and the supply of oxygen also promote the health of the patient.

When eating, raw meat should be completely avoided. A glass of water enriched with a teaspoon of baking soda can be drunk every 2-3 days after dinner. Baking soda is an important everyday companion and has an antibacterial effect on the organism. It therefore increases general well-being and has a health-promoting effect.