What area is cautioned against at ST-12?

ST-12, also known as "Que Pen" or "Empty Basin," is located in the supraclavicular fossa, just above the clavicle and lateral to the sternocleidomastoid muscle. This acupuncture point is considered a region of caution primarily due to the proximity of important vascular structures.

The axillary artery is a major blood vessel supplying blood to the upper limb and is located in close proximity to ST-12. When needling at this point, practitioners must be cautious to avoid puncturing or damaging this artery, which can lead to significant complications. Therefore, the designation of caution regarding the axillary artery emphasizes the need for precision and awareness of anatomy when treating in this area.

The other options, while also important anatomical structures, do not bear the same level of direct concern in relation to the ST-12 point. The aorta, while a significant vessel, is positioned much deeper in the thorax and not directly at risk when needling ST-12. The brachial plexus, a network of nerves, is also deeper in its anatomical location, and while care is still required, it does not present the same immediate risk as the axillary artery does at ST-12. The pulmonary artery also lies