With the development of online healthcare services, patients could receive support and create value with other users on online healthcare platforms. However, little research has been conducted on the internal mechanisms of patient value co-creation from the perspective of online healthcare platforms. To analyze patient value co-creation in online healthcare platforms, this study explores the underlying mechanisms of patient value co-creation among patients. The results show that value co-creation includes patient citizenship behavior and participation behavior. Information quality, peer communication, and system quality influence functional experiences and emotional experiences. In addition, functional experiences and emotional experiences could influence patient value co-creation. This study clarifies the mechanism of value co-creation among patients and provides insight into value co-creation in online healthcare platforms.