Visible bruises on the arms are actually a sign of poor venous reflux in the superficial veins of the arms, similar to varicose veins in the lower extremities. Due to poor venous reflux in the upper extremities, blood stagnation in the superficial veins caused by venous insufficiency results in visible veins in the arms. Generally, the bruises in the arms are not clinically significant and can be treated by elevating the affected limbs and taking medications to promote venous return to alleviate further development. However, in some patients, the bruising is caused by the establishment of collateral circulation in the superficial veins due to deep vein thrombosis or blockage, which requires systematic and regular diagnosis and treatment in vascular surgery to open the deep veins, alleviate the symptoms of deep vein thrombosis, and delay its further development to avoid serious adverse consequences.