Cystic diseases of the kidney: when you need to see a doctor

Cysts are thin walled fluid or air-filled sacs which are not part of the healthy body though commonly harmless. When our kidneys become affected by them, the condition is called kidney cysts or renal cysts. Truly speaking, the majority of kidney cysts are benign (not cancerous) simple cysts that vary from one to multiple in number and are common in elderly people which are often missed. Nevertheless, these simple cysts aren't same as the ones occur in the dreaded polycystic kidney disease (PKD) which is a fairly common inherited disorder responsible for kidney failure. PKD will be discussed a bit later.

How common are simple Cysts?

Studies reveal that approximately one-third of adults above 50 years of age have simple cysts in their kidneys and as most cases are not symptomatic, they go unnoticed.

Any risk factors? Or do they ‘just' pop up?

In fact, they might. The real reason for simple cysts is not yet understood though many hypotheses made by scientists prevail. However, male sex is more prone to get them than the fairer sex and also more frequent in individuals above 50. Of course, these are not risk factors as they are more ‘contributing factors'.

Do you have them? When to call the doctor

If you are an above 50-year male, you might. As most are not symptomatic you will never know. However, this is not always the case as some cysts may exert a number of symptoms which are listed below.

  • Frequent pain in your abdomen or back as cysts press against your organs.
  • Increased frequency of passing urine due to pressure on bladder or infection (UTI).
  • Pain in the side of your trunk, typically between the costal margin and iliac border (hip margin)
  • Fever if infected. Sometimes associated with chills.

If you are having one or more of above features for some time it may indicate that cysts may be enlarging or already infected. So it is ideal to consult a doctor as soon as possible, for confirmation and excluding other conditions (Differential diagnoses) like kidney stones.

Why you should not delay

Though rare, cysts can occasionally cause complications.

  • Rupture of a cyst : This can happen spontaneously or following a blow to the abdomen. Can be intensely painful and may need painkillers. Surprisingly, this is self-limiting in most instances as the communication between the cyst and abdominal cavity ceases automatically.
  • Obstruction of urine flow : This can block the kidney outflow of urine causing them to swell (hydronephrosis). This can be perilous as it can lead to kidney failure.

So if you are experiencing the characteristic cyst pain, better meet your physician. 

What will the good doctor do?

The doctor will ask a number of questions aimed at differentiating cysts from other similar conditions. After a thorough history and a physical examination, he will probably recommend an imaging test like an ultrasound, CT or MRI. These can recognize the cysts along with its parameters like size, location, and content. In suspicion of a malignancy (cancer) ultrasound assisted aspiration from cyst using a needle, and examination of the aspirate for malignant cells are mandatory and lifesaving.

Another thing your doctor will do is ordering some lab tests like serum electrolytes and creatinine for evaluating your kidney function which will be abnormal in renal insufficiency.

Asymptomatic small simple cysts do not need any treatment. But problematic large cysts may need medical or surgical intervention. The most commonly practiced methods are,

  • Ultrasound-assisted drainage of cysts using a needle and injecting alcohol to shrink them.
  • Surgical excision of the cyst: Several techniques are available. Video-assisted surgery using guided video camera and instruments is usually practiced.

How to prevent?

Despite the evolution in medical science, there is no ‘sure' way to prevent kidney cysts. Nonetheless, drinking adequate water without being dehydrated and minimum salt consumption can have an inhibitory effect on them.

What Polycystic Kidney Disease?

Unlike the harmless simple cysts, PKD can fill the kidneys with a number of cysts ultimately shutting down their activity leading to death. This is an inherited disorder and the fourth common cause of renal failure. When the kidneys are failing less fluid will be excreted causing fluid overload leading to high blood pressure, a characteristic feature of PKD. However, this condition is comparatively less frequent than simple cysts.

Last Reviewed:
December 20, 2016
Last Updated:
October 18, 2017
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