In this paper, we reviewed naturally occurring RNAs with their cellular functions and the associated research trends based on the analysis of CAS Content Collection. We then appraised different types of RNA in medical applications: their advantages, challenges, and research trends. Subsequently, we assessed the development pipelines of RNA therapeutics and vaccines with company research focuses, disease categories, development stages and publication trends. Finally, we discussed RNA chemical modifications and delivery systems in detail, as they are critical to the success of RNA medicine. We hope this review can serve as an easy-to-understand overview so that scientists from many different disciplines can appreciate the current state of the field of RNA medicine and join in solving the remaining challenges for fulfilling its potential.