Background: Technical debt(TD) is incurred when developers accept compromises in a system in one dimension to meet urgent demand in some other dimensions (e.g., a deadline). If technical debt is not managed correctly, it will cause hidden danger to software’s long term success. It does not get enough attention when TD applies to the requirements engineering. Objectives: In this study, we investigate the current state of requirements debt(ReD). We aim to give a precise definition of ReD. We also focus on the factors that can induce ReD in the requirement engineering and requirement management process. Moreover, we want to summarize the measurement tools to detect and locate the ReD. Finally, we try to find approaches and ideas to manage ReD. Methods: We conducted a systematic mapping study (SMS) and a survey for all of the objectives. When performing the systematic mapping study, we applied snow- balling method to ensure we find related and enough papers. Results: According to the analysis and results of SMS and the survey, we concluded the definition of requirements debt. We also presented and classified 54 ReD induced factors into 8 categories. 10 ReD measurement techniques searched from literatures were listed with a brief description for each one, suggestions from software practi- tioners on ReD detection also gathered and displayed. The management techniques and theoretical suggestions were presented based on related factors. Conclusions: From research result, we find academia and industry lay different emphasises on how to manage ReD. To stimulate Industry pay more attention on control and manage ReD effectively, this paper calls for the two sides to work on the same point.