What is hemodialysis primarily used for?

Hemodialysis is a medical treatment specifically used to replace the function of the kidneys in individuals who are experiencing kidney failure or significantly reduced kidney function. During this process, blood is extracted from the body, filtered through a dialyzer (artificial kidney), which removes waste products, excess fluids, and toxins that the kidneys would normally filter out. This cleaned blood is then returned to the body.

By performing this filtration, hemodialysis effectively takes over the role of the kidneys in removing harmful substances from the blood, thus managing the patient's condition and maintaining their overall health until a kidney transplant or other long-term treatment can be arranged. This makes it a critical intervention for those with chronic kidney disease or acute kidney injury.

In contrast, the other options do not accurately reflect the primary use of hemodialysis. While increasing urine flow, testing urine samples, and enhancing blood circulation are important aspects of renal and circulatory health, they do not capture the essential purpose of hemodialysis, which is to fulfill the excretory functions of the kidneys.