Medical literature is scientific research that appears in journals dedicated to medicine & related disciplines & medical textbooks. It is typically categorized as primary, secondary or tertiary.
Primary medical literature is original research data gathered & described by scientists or medical professionals. It is evaluated by other scientists or medical professionals (peer reviewed) before it can qualify for publication in a scientific journal. It may also include conference papers, article preprints, or preliminary reports, etc.
Secondary medical literature comprises descriptions, analysis & interpretation of the primary literature by professionals in medicine or related disciplines & may identify areas for new research. Secondary literature sources include different types review articles (see table), abstracting & indexing databases, clinical practice guidelines, etc.
Tertiary literature, found in medical textbooks for example, represents an overview of key research findings derived from primary & secondary literature & introduces principles & practices within medicine.