The Collaborative healthcare cloud environment offers potential benefits, including cost reduction and improvising the healthcare quality delivered to patients. Though, such scenarios experiences substantial challenges in case of the privacy and security of the exceptionally sensitive information contained in Electronic Health Records (EHRs). Through this paper, a Hierarchical tree-based architecture is proposed. The work is based upon multi-keyword search technique which incorporates secure search using stemming and lemmatization algorithms to improve the process efficiency and privacy detailing. It helps biomedical departments and patients to connect easily and process their queries without any intruder's intervention. Furthermore, performance of the proposed solution is empirically indorsed through the simulation experiments. © 2018 IEEE.