SP-18 is located in which intercostal space?

• A. Fourth intercostal space
• B. Fifth intercostal space
• C. Third intercostal space
• D. Sixth intercostal space

Answer: (A)

SP-18 sits on the chest wall along the Spleen channel in the fourth intercostal space. This particular space is the standard landmark for this point, placing it in the mid-chest region near the nipple line for many people. The reason this space is the best fit is that the Spleen channel travels through the chest and SP-18 is defined in point charts as being located there to address chest-related issues such as chest fullness, rib pain, or related qi stagnation. If the point were higher or lower (in the third, fifth, or sixth intercostal spaces), it would align with different chest-area points on the channel and serve different indications. So the fourth intercostal space is the correct location for SP-18.