In recent years, healthcare wireless sensor networks (HWSNs) have received extensive attention. Due to the direct participation of patients' personal health data, privacy issues, and security are very sensitive in HWSNs. How to aggregate the sensitive patient information securely and efficiently is still a challenging task to the HWSNs communication scenario. In this article, a lightweight data aggregation protocol with privacy-preserving is proposed to achieve enhancing security in HWSNs. With the proposed protocol, patients' personal health data collected by the data collect client can be aggregated by data aggregator and efficiently obtained by the medical service provider in a privacy-preserving manner. In particular, we first propose an efficient certificateless aggregate signcryption scheme, and then, design a data aggregation protocol for patient condition monitoring with information confidentiality, integrity, mutual authenticity, and public verifiability. Performance comparisons show that our newly proposed protocol significantly reduces computing overhead compared to the latest protocols in the field.