Which point lies on the abdomen 2 cun lateral to the midline and 4 cun superior to the umbilicus, level with REN-12?

• A. ST 20
• B. ST 21
• C. ST 22
• D. ST 23

Answer: (B)

Locating abdominal points uses fixed landmarks and cun measurements. Ren-12 sits on the midline 4 cun above the umbilicus, giving a horizontal reference. A point that is 2 cun lateral to the midline at that same level lies on the stomach meridian and is ST-21. So this description matches ST-21 exactly. The other nearby points sit at different vertical heights or different lateral positions, so they don’t fit this coordinate. To locate it, find the umbilicus, go 4 cun up to Ren-12, then move 2 cun to the side to reach ST-21 on the stomach channel.