Which three veins are most commonly used in phlebotomy?

The three veins most commonly used in phlebotomy are the cephalic, median cubital, and basilic veins due to their accessibility and location. The median cubital vein, located in the antecubital fossa (the crease of the elbow), is typically the preferred choice because of its size, straightness, and proximity to the skin surface, which makes it easy to puncture and able to accommodate a variety of blood collection tubes.

The cephalic vein, located on the lateral side of the forearm, is often chosen when the median cubital vein is not suitable, such as in patients with obesity or difficult venous access. It is also relatively easier to palpate in such cases. The basilic vein, found on the medial side of the forearm, is larger but closer to major nerves and arteries, which makes it a less favorable option compared to the other two veins, though it is still commonly used when necessary.

In contrast, the other choices include veins that are either less accessible for routine blood collection or more complicated due to their anatomical locations. For instance, the subclavian, femoral, and jugular veins are typically reserved for specialized procedures and require more advanced skills and techniques. Radial