An arteriovenous fistula (AVF) is an abnormal connection between an artery and a vein. This condition can occur naturally or be created surgically, often for patients requiring dialysis for kidney failure. The fistula allows blood to flow directly from the artery to the vein, bypassing the capillaries. AVFs are beneficial for dialysis because they provide a reliable access point for blood removal and return. They typically have a lower risk of complications compared to other access methods, such as catheters. However, monitoring is essential to ensure proper function and to prevent issues like thrombosis or infection.