Overview

Renal cysts are sacs filled with fluid that form inside or on the outside of the kidneys. It is divided into two broad categories: simple or complex. Simple renal cysts are usually not harmful, have thin walls, and contain clear fluid. Most of the time, they don't cause any problems. Complex cysts may have thicker walls or internal structures, so they need to be examined more closely. Renal cysts are prevalent, particularly among older adults, and are frequently incidentally identified on imaging for unrelated conditions. Most cysts don't affect kidney function, but larger or more complex cysts can cause pain or problems that require medical attention.

Symptoms
Most uncomplicated renal cysts are asymptomatic. When symptoms occur, they might include a dull ache in the back or side, a full feeling in the stomach, or a feeling of pressure. People may develop a fever, sharp pain, or blood in their urine if a cyst becomes infected or ruptures. Sometimes, large cysts can impair kidney function.

Causes
The exact causes of simple renal cysts are still unknown. People think they happen when small pouches form on kidney tubules and fill with fluid over time. Getting older is a big risk factor. Polycystic kidney disease is an inherited condition that causes multiple cysts to form. This is different from having just one simple cyst.

Diagnosis
Imaging tests like ultrasound, CT scan, or MRI are usually used to make a diagnosis. These tests help distinguish between simple and complex cysts. To check how well the kidneys are working, blood and urine tests may be done. More tests may be needed for complex cysts.

Treatment
Most uncomplicated renal cysts require no treatment and only periodic surveillance. If a cyst hurts, becomes infected, or blocks something, doctors may suggest draining or surgically removing it. We carefully evaluate complex cysts to ensure they aren't cancerous. Taking care of underlying kidney problems helps keep the kidneys healthy overall.

Most simple renal cysts don't cause problems, and the outlook is generally good. You need to monitor complex cysts, but they are usually easy to manage. Regular check-ups and the right tests help ensure kidney function stays stable.