Why do some people need to use a dialysis machine? What does the machine do?

Kidneys help in the removal of major waste products like ammonia and urea. These are excreted regularly from our body with the help of kidneys. In the case of kidney failure, these wastes are not excreted and can cause harmful effects to the body. Then the blood is filtered externally by the process of dialysis. In this process the blood is purified externally. The impure blood is taken out of the body.

Then in the dialysis machine it is purified and the pureblood is sent back to the body. This process is done periodically, depending on the condition of the patient.