Name the process by which the blood of a person having kidney failure is cleaned by using a kidney machine .

Answer

### Step-by-Step Solution:

1. **Understanding Kidney Function**: The kidneys are vital organs responsible for filtering waste products, such as urea, from the blood and excreting them in urine. They also help regulate fluid balance in the body.

2. **Identifying Kidney Failure**: When a person's kidneys fail, they cannot effectively filter waste from the blood. This leads to the accumulation of nitrogenous waste (like urea) in the bloodstream, resulting in a condition known as uremia.

3. **Recognizing the Need for Treatment**: Since the kidneys are not functioning properly in patients with kidney failure, there is a need for an alternative method to clean the blood and remove excess waste.

4. **Introducing the Kidney Machine**: The process used to clean the blood of a person with kidney failure is called **hemodialysis**. This process involves using a machine that acts as an artificial kidney.

5. **Explaining Hemodialysis**: During hemodialysis, blood is drawn from the patient and passed through a dialyzer (the kidney machine), where it is filtered to remove waste products and excess fluids. The cleaned blood is then returned to the patient’s body.

6. **Conclusion**: Therefore, the process by which the blood of a person having kidney failure is cleaned using a kidney machine is called **hemodialysis**.