Online health Q&A communities help patients, doctors and other users conveniently search and share healthcare information online and have gained much popularity all over the world. Good-quality questions that raise massive discussions could trigger users’ engagement online, which is beneficial for platform operation. However, little attention has been paid to the antecedents of question quality in online health Q&A communities. To have a deep investigation of healthcare question quality, this research aims to investigate the impact factors from two special aspects that are neglected in previous research, i.e., user’s structural influence and questions’ sentiment. Using a dataset collected from MedHelp, one of the largest online health Q&A communities, we found that users with high structural influences and questions with negative sentiment have positive associations with the answer number of questions. Our research would offer meaningful suggestions to platform managers and users.