Transradial access may lead to anatomical and functional changes on the vessel wall due to puncture or material-associated trauma, inflammation and loss of endothelium's nitric oxide vasodilatory response. Despite the superficial and palpable radial artery course, caution and dexterity are important assets when puncturing, wiring, inserting the sheath, or maneuvering the catheters. Radial artery anatomic variations, tortuosity, and radial artery spasm are related with femoral access switch. The outer diameter of sheaths and catheters needs to match radial artery internal diameter; otherwise, friction or vascular stretch will occur, activating the surface endothelium and the coagulation cascade. Friction between the arterial wall and the equipment worsens endothelial function and precipitates patient discomfort, radial artery spasm, and ultimately, radial artery occlusion.