Coping with... KIDNEY CYSTS

These round, thin-walled, fluid-filled cysts occur in the tissue of the kidney

The kidney is made up of blood vessels carrying blood to tiny filters connected to a tube. Each kidney contains about a million filters and tubes. A cyst occurs when one tube expands, often to a very large size, although it’s not known what causes it.

Occasional kidney cysts are common, up to five in each kidney is considered normal, ranging from a few millimetres to 5cm wide, and rarely lead to any problems. Having more cysts is abnormal, but may not be due to serious disease.

There are more serious cysts – some are a form of cancer, but these do not look the same as normal cysts. We also see other types of cysts including very small cysts, infections and stones in two conditions: medullary sponge kidney, which does not lead to kidney failure; and medullary cystic kidney disease, with very small cysts, which may lead to kidney failure, needing dialysis.

Genetic causes of polycystic kidneys, which can run in families, include autosomal recessive polycystic kidney disease, found in childhood, and autosomal dominant polycystic kidney disease, found in adults – where kidney failure may develop. Both have hundreds of cysts in each kidney.

The symptoms