Medial means toward the middle or center. It is the opposite of lateral. The term is used to describe general positions of body parts. For example, the chest is medial to the arm.
Your health care provider may use this term to clearly explain the relationship between things found during a physical exam or on medical tests.
Drake RL, Vogel AW, Mitchell AWM. The body. In: Drake RL, Vogel AW, Mitchell AWM, eds. Gray's Atlas of Anatomy. 2nd ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2015:chap 1.