What is hemodialysis?

Hemodialysis is indeed defined as a treatment that utilizes a machine to filter waste products from the blood when the kidneys are unable to perform this function effectively. This process involves diverting blood from the body into a dialysis machine, where a dialyzer, or artificial kidney, removes waste, excess fluid, and toxins. The cleaned blood is then returned to the body. Hemodialysis is typically used in patients with chronic kidney disease or acute kidney injury where natural kidney function has significantly declined or ceased altogether.

The other options describe separate concepts: medications used to stimulate kidney function target the restoration of renal activity but do not involve filtering blood; kidney transplantation is a surgical intervention that involves replacing a diseased kidney with a healthy one, not a treatment for blood waste removal; and diagnostic tests for kidney function, such as serum creatinine measurement, assess kidney health rather than providing treatment. Hemodialysis stands out as a key treatment modality for managing kidney failure, making it the correct answer.