To realize the medical video applications, this paper proposes several lossless compression methods over high efficiency video coding (HEVC). A generalized intra block copy (GIBC) is first proposed to predict the coding unit by a reference block, whose samples could be fully or partially reconstructed. A cyclic block padding technique is also proposed to predict the unreconstructed samples in the reference block by geometrically co-located blocks. Based on the feature distribution analyses for palette coding, we further propose an HEVC-based medical video coder (HMC), which combines the GIBC, line-coded palette coding and intra palette predictor without mutual conflicts. Experimental results show that, compared to the lossless HEVC, the proposed GIBC and HMC respectively save up to 13.9% and 22.3% bits over medical videos.