The blood-test vein
Median cubital vein · vena mediana cubiti
The vein in the crook of your elbow where blood is usually taken.
What it does
The median cubital vein crosses the front of the elbow, linking the cephalic and basilic veins. It sits just under the skin, fixed in place, with the tough sheet over the biceps tendon separating it from the artery and nerve below.
Surprising fact
It is the favourite vein for blood tests because it is large, stays put and has deeper structures shielded beneath it.
Why it matters
A tourniquet above the elbow makes this vein swell so it can be found easily, which is why you're asked to make a fist during a blood test.
Nearby
Read more
Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.