What is the main role of the kidneys in maintaining fluid balance when fluid levels are too high?

The main role of the kidneys in maintaining fluid balance when fluid levels are too high is to eliminate excess fluid from the body. The kidneys filter blood to remove waste products and excess substances, including water. When fluid levels increase, the kidneys respond by producing more urine, which helps to expel the surplus fluid. This process is essential for regulating the body's internal environment and maintaining homeostasis, particularly in terms of blood pressure and overall hydration levels.

By filtering out excess fluid, the kidneys play a crucial role in ensuring that the body does not retain more water than it needs, thereby preventing conditions related to fluid overload. This regulatory function is vital for overall health and well-being.