Most of the time, kidney cysts do not cause symptoms or harm the kidney

Cysts are often filled with air or fluid; the frequency increases with advancing age and are often found with high blood pressure.

Kidney cysts are generally a closed pocket or pouch of tissue that can form anywhere in the body; and they can be filled with air or fluid.

When cysts form on the kidneys they usually contain fluid and one or more cysts may develop on small tubes in the kidneys. The simple kidney cyst is different from the cysts that develop when a person has polycystic kidney disease, which is a genetic disease. Although its cause is not fully understood, the simple cyst is not an inherited condition. Simple kidney cysts become more common as people age. Nearly 30 percent of people over the age of 70 have at least one simple kidney cyst.

Most often, simple cysts do not cause symptoms or harm the kidney. In some cases, however, pain can occur when cysts enlarge and press on other organs. Sometimes cysts become infected or suddenly start to bleed. Less often the cysts impair kidney function. People with simple cysts are often found to have high blood pressure, although the cause-and-effect relationship is not well understood.

Kidney cysts are found by taking pictures of the kidneys using computerized tomography (CT) scans and ultrasonography. When simple cysts are found but no complications are present, no treatment is needed.

If cysts cause symptoms, treatment may be needed. One procedure involves puncturing the cyst using a long needle inserted through the skin. The doctor uses ultrasonography to guide the needle to the cyst. The cyst is drained and then filled with a solution containing alcohol to make the tissue harder.

If the cyst is large, surgery may be needed. Most procedures can be performed using a laparoscope, which allows for a smaller incision and quicker recovery. The surgeon drains the cyst then removes or burns away its outer tissue. Most patients stay in the hospital 1 or 2 days.

Other kidney cyst disorders include polycystic kidney disease and multicystic kidney dysplasia. Although rare, these disorders can eventually lead to kidney failure.