The dialysis that is applied to the patients with renal failure are of two types: peritoneal dialysis and hemodialysis. Peritoneal dialysis is the procedure of cleaning the blood from the harmful substances and maintaining fluid balance through a special solution administered into the abdominal cavity. Hemodialysis is the procedure of cleaning the blood through a machine outside the body and giving the cleaned blood back to the body. The blood is drawn through a syringe from the arm of the patient. The hemodialysis machine filters the blood through a dialyser continuously and removes the harmful substances and the extra water. The filtered clean blood is given back to the patient through a second syringe. During that procedure, sometimes, fluid containing nourishment becomes necessary to be given to the patient.  Accordingly, fasting is not invalidated if hemodialysis is carried out without giving any fluid containing nourishment to the patient. In the other forms of dialysis, fasting is invalidated since fluid containing nourishment is given to the body.