Intravenous infusion is the most common route of drug delivery for clinical treatment and resuscitation of patients, and the infusion rate of clinical patients in China is as high as 90% or more, which has been accepted by the majority of patients because of quick effect and less pain. Which blood vessels are often used for infusion? Here I will give you a brief introduction: clinical infusion mostly uses the superficial veins of upper and lower limbs, the superficial veins of upper limbs mainly include the vein network of the back of the hand, the superficial veins of the forearm and the front of the elbow, the superficial veins of lower limbs mainly include the saphenous vein of the inner ankle and the dorsal foot veins. Superficial veins of upper limbs: including cephalic vein, noble vein, median elbow vein and its branches. 1.Cephalic vein: it starts from the radial side of the venous network of the back of the hand, goes along the radial side of the lower forearm, the front of the upper forearm and elbow and the lateral groove of the biceps muscle, then goes through the deltoid pectoralis interosseous groove to the subacromial fossa and injects into the axillary vein or subclavian vein through the deep fascia. The cephalic vein crosses the median elbow vein at the elbow fossa and communicates with the guillotine vein. The cephalic vein collects venous blood from the superficial tissue of the radial side of the hand and forearm. 2.Valuable vein: it starts from the ulnar side of the venous network on the back of the hand, goes up along the ulnar side of the forearm, turns to the front at the elbow, receives the median elbow vein at the elbow fossa, then goes through the medial biceps sulcus to the midpoint plane of the arm and injects the brachial vein through the deep fascia, or goes up with the brachial vein and injects the axillary vein. Your vein collects venous blood from the superficial structures of the ulnar side of the hand and forearm. 3.Median elbow vein: more variations, usually connects the cephalic vein and the guillotine vein at the elbow fossa. 4.Median vein of forearm: It starts from the palmar plexus and travels up the front of forearm and injects into the median vein of elbow. The median forearm vein sometimes bifurcates and is injected into the cephalic vein and the superior vein respectively, thus there is no median elbow vein. The median forearm vein collects venous blood from the palmar side of the hand and the superficial structures of the anterior forearm. Superficial veins of the lower extremities: including the small saphenous vein and the great saphenous vein and their branches. 1.Small saphenous vein: it starts from the dorsal arch of the foot at the lateral edge of the foot, passes behind the outer ankle, goes up along the back of the calf, goes to the lower corner of the popliteal fossa and penetrates the deep fascia, then goes up between the two heads of the gastrocnemius muscle and injects into the popliteal vein. The small saphenous vein collects venous blood from the lateral part of the foot and the superficial structures at the back of the calf. 2.Saphenous vein: It is the longest vein in the whole body. It starts from the dorsal arch of the foot at the medial edge of the foot, passes in front of the inner ankle, travels along the medial side of the calf, behind the inner knee joint, and up the medial side of the thigh to 3~4cm below the pubic symphysis and injects into the femoral vein through the saphenous vein fissure of the broad fascia. Before injecting into the femoral vein, the saphenous vein receives five branches, including the superficial medial femoral vein, the superficial lateral femoral vein, the superficial pubic vein, the superficial abdominal wall vein and the superficial rotating iliac vein. The saphenous vein collects venous blood from the medial portion of the foot, calf, and thigh, as well as from the superficial structures of the anterior thigh. The saphenous vein is superficial and fixed in front of the medial ankle and is a common site for infusions and intravenous injections. In principle, the 2014 Ministry of Health industry standard for intravenous infusion recommends that upper extremity veins should be selected as puncture sites, avoiding venous valves, joint sites, and veins with scars, inflammation, and hard nodes. Adults should not choose lower extremity veins for puncture.