Compared with studies that deal with metonymic expressions in language, research on metonymy as a structuring dynamic for social activity has received relatively less attention. This study investigates how metonymic schemes of thought are exploited in online medical consultation (OMC), especially in cases where health professionals offer a somewhat evasive reply. It suggests a cognitive-pragmatic model for analyzing the act of offering consultation in the online health context. The results, based on 100 high-rated OMC cases in Chinese, show that four metonymic schemes of thought intersect with and underpin the satisfactory performance of the act. The suggested model is further enriched by four types of cognitive-pragmatic forces that facilitate the adoption of the emerging patterns of metonymic reasoning: cognitive, emotive-affective, pragmatic, and social forces.