Simple kidney cysts are fluid-filled sacs that form on the kidneys. They are usually round or oval and can vary in size. Most people with simple kidney cysts do not experience any symptoms, and these cysts are often discovered incidentally during imaging tests for other conditions. These cysts are generally benign, meaning they are not cancerous and do not pose serious health risks. Simple kidney cysts are common, especially in older adults, and typically do not require treatment unless they cause discomfort or complications. Regular monitoring may be recommended to ensure they remain stable.