Kidney cysts are fluid-filled sacs that develop on or in your kidneys. The cysts are noncancerous and may or may not cause symptoms or other health problems, depending on the type of cysts you have.
There are two types of kidney cysts:
- Simple kidney cysts– simple kidney cysts are the most common. These types of cysts usually don’t cause symptoms, unless they grow large, and then you might feel some abdominal or back pain or develop a fever. While simple kidney cysts are relatively harmless, they can sometimes affect kidney function.
- Polycystic (PKD) is a genetic disease. This means that it is caused by a problem with your genes. PKD causes cysts to grow inside the kidneys. The cysts are sacs of fluid and people with PKD, may have thousands of cysts in their kidneys at once, making the kidneys much larger than they should be.
A kidney that is filled with cysts can weigh up to 30 pounds. PKD causes chronic kidney disease (CKD) , which can lead to kidney failure, or end-stage renal disease (ESRD). PKD causes about 2 percent (2 out of every 100) of the cases of kidney failure in the United States each year.