Kidney cysts


Kidney cysts, also classified as simple kidney cysts, is a closed spherical pocket or sac with a thin wall and filled with fluid. It develops in the nephrons of the kidneys or on its surface as people age. Simple kidney cysts are noncancerous and usually do not cause symptoms.

Simple kidney cyst has no exact cause. However, certain disorders that may impair kidney function might cause kidney cysts. The cysts might be as small as a pea or as big as a grapefruit. One cyst usually develops on the outside of a kidney. However, one or both kidneys may develop more than one cyst.

The reason it is classified as “simple” is that there is a very little probability that it may turn into something serious. Simple kidney cysts are different to complex cysts and cysts that develop as a result of polycystic kidney disease (PKD). PKD and complex cysts can damage kidney tissues, lead to cancer, or result to kidney failure.

Simple kidney cysts are very common. Rarely, treatments such as surgery is recommended to those who experience symptoms. Simple kidney cysts are frequently discovered during tests for another illness.


Most people with simple kidney cyst are asymptomatic. In some symptomatic case, the sign and symptoms of are as follow:

  • Pain in the side, back, or upper abdomen
  • Fever or chills
  • Frequent urination
  • Blood in the urine

It is recommended to visit a healthcare provider for proper diagnosis and treatment if any of the signs and symptoms occur.


The exact cause of simple kidney cyst is unclear. Hypothetically, kidney cysts form when the kidney’s outer layer deteriorates and creates a pouch. The pouch then separates, swells with fluid, and turns into a cyst. There is no evidence that this condition is hereditary.

Another explanation also suggests that simple kidney cysts arise as a result of trauma to the tubules of the nephron or microscopic obstructions within. The nephrons are composed of filters and tubes that filtrate excess water and waste from the blood as it passes through the kidneys to be excreted as urine.

Risk factors

Simple kidney cysts can affect anyone at any age. However, as the person ages, the chance of developing it rises. Up to 50% of all people 50 years of age and older have at least one kidney cyst. It is also more prevalent in men than in women.