The Kidney Clinic

Cystic Kidney Disease

Simple and complex kidney cysts

Kidney cysts result from  genetic or non-genetic processes. It can occur and affect children and in adults. It is usually diagnosed when a person goes for an ultrasound scan, CT scan or MRI scan of the abdomen. Kidney cysts can be divided to simple kidney cysts or complex kidney cysts. There is another condition where the kidney is filled with multiple kidney cysts which will be covered under cystic kidney disease. 

The most common cause of these cysts are radiologically evident kidney cysts in adults are simple kidney cysts. 

Simple kidney cysts

These cysts are fairly common and usually affect older individuals. They don’t tend to enlarge or disrupt the kidneys. In rare cases, cysts can be malignant (cancerous) and lead to kidney cancer. 

Complex kidney cysts

Complex renal cysts can have a thicker wall, or solid material inside instead of just fluid. Once complex renal cysts are discovered, additional imaging tests may be performed to monitor them and distinguish benign cysts from cancer. 


If it is a simple cyst, generally treatment is not necessary. However if the cyst is large and disrupts the normal flow of urine or causes symptoms, it should be removed usually by a radiological intervention. Complex cysts are followed up closely with repeated scans and if there is a suspicion of cancer, it should be removed.

What is cystic kidney disease?

Cystic kidney disease is a condition where multiple cysts form in or around the kidneys. It is divided to genetic and non-genetic cause. Under the genetic cause, the cysts are formed due to mutations or changes to certain genes that are inherited from their parents. These genes can possibly pass to the next generation. For the other group of patients, their kidney cysts develop during their lifetime, or may be present at birth. 

Are there different types of cystic kidney disease?

There are several types of cystic kidney disease. Some are the result of mutations (changes) to certain genes that are usually inherited (passed from parents to children). Others may develop during a person’s lifetime, or they might be congenital (present at birth). Cysts can also appear in the kidney later in life. 

Genetic cystic kidney diseases

Polycystic kidney disease (PKD)

The most common form of inheritable kidney disease and usually diagnosed between ages 30 and 50.

Glomerulocystic kidney disease

The cysts grow in the space near the urinary tract. It's very uncommon but can affect infants or adults.

Medullary cystic kidney disease (MCKD)

MCKD causes cysts to develop in the corticomedullary (inner) part of the kidneys.


A very rare condition, which affects infants, children and teenagers. It usually leads to kidney failure before adulthood.

Non-genetic cystic kidney diseases

Acquired cystic kidney disease

These cysts develop over time due to chronic kidney disease or kidney failure. It affects both adults and children who are on dialysis.

Medullary sponge kidney

Cysts form on the innermost part of the kidneys. They block the tubes that filter urine. It's rare.

Multicystic dysplatic kidney

This condition occurs when the kidneys do not develop correctly in the womb. This leads to cysts replacing this normal kidney tissue.


Cystic kidney disease signs and symptoms may include:

    • Back or flank pain (pain in your back or sides)
    • Burst or bleeding cysts
    • Difficulty urinating, or not producing much urine. 
    • Fullness in the abdominal region
    • Feeling bloated
    • Headaches
    • Blood in urine (haematuria)
    • High blood pressure
    • Kidney infections
    • Kidney stones
Treatment Options

Cysts can grow in size and numbers over time, it is usually associated with deteriorating function as the cysts repace the normal kidney tissues, especially the genetic. Treatment would involve controlling blood pressure, prevention of cardiovascular events and treating immediate complications of kidney cysts, for example infected cysts, and burst cysts. If the patient’s kidney function deteriorates to end-stage kidney failure, they will be started on dialysis or undergo kidney transplantation. In recent times, there is treatment available to slow the growth of these kidney cysts especially for patients suffering from polycystic kidney disease. 

Please consult our kidney specialist to discuss further about your condition.

Do you have a question about your kidney or medical condition?

Reach out to us for a consultation with Dr Alvin Ng. 

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