The hemodialysis catheter is a catheter used to transfer blood to and from the dialysis machine and the patient. [1] The hemodialysis catheter contains two lumens: the venous and arterial, and although both lumens are inside the vein, the "arterial" lumen functions like a natural artery, carrying blood away from the heart, while the "venous" lumen carries blood toward the heart. The arterial lumen (usually red) draws blood from the patient and carries it to the dialysis machine, while the venous lumen (usually blue) carries blood back to the patient (from the dialysis machine). The flow rates of the hemodialysis catheter range between 200 and 500 ml/min. The chronic hemodialysis catheter is used if the patient requires long-term dialysis, and the chronic catheters contain a polyethylene terephthalate cuff embedded under the skin at a depth of about 3-8 cm, and it is believed that the lumen contains a barrier to prevent infection. The most popular type of dual-lumen hemodialysis catheter sold in markets today is the two-lumen catheter, which consists of two free ends.