Entry Vocabulary

The entry terms, sometimes called "See cross-references", indicate that information related to one term will be found under a different term. They are not always synonyms of the descriptors to which they refer. Some terms, because of their narrow focus, are not useful as subject headings; they are instead created as cross-references.

In the alphabetic listing in this publication, each descriptor is followed by one or more alphanumeric expressions (tree numbers) that indicate where in the Tree Structures the term is to be found. A plus sign following a tree number in the Alphabetic List indicates there are more specific descriptors in the Tree Structures at that number under that descriptor.

Abdominal Abscess
  X Abscess, Abdominal
  X Abscess, Intra-Abdominal

Abscess, Abdominal see Abdominal Abscess

Three kinds of informative references suggest other descriptors in MeSH that relate to the subject and that may be useful in indexing, cataloging, or searching a particular topic.

See related references are used primarily to indicate related headings not occurring in the same subcategory of the MeSH Tree Structures (see below). Many of the most obvious cross-references, such as those from an organ to its diseases, are omitted.

See related references indicate the presence of other descriptors related to the topic conceptually, e.g., NAVAL MEDICINE see related DIVING. Some relationships are recognized routinely:

• Between an organ and a procedure (E.G., BILE DUCTS See Related CHOLANGIOGRAPHY);
  
• Between an organ and a physiological process (BONE AND BONES See Related OSTEOGENESIS);
  
• Between a physiological process and a related disease (BLOOD PRESSURE See Related HYPERTENSION);
  
• Between an organ and a drug acting on it (BRONCHI See Related BRONCHOCONSTRICTOR AGENTS);
• Or between a physiological process and a drug acting on it (BLOOD COAGULATION See Related ANTICOAGULANTS), etc.

Indicators of Entry and Related Terminology

Consider also is used primarily with anatomical descriptors. It indicates the presence of other descriptors that relate to the topic linguistically, e.g., BRAIN consider also terms at CEREBR- and ENCEPHAL-. Note consider also refers to groups of descriptors beginning with a common stem rather than to a single descriptor.

The descriptor/qualifier combination notations refer an invalid (and prevented) descriptor/qualifier combination to the preferred pre-coordinated descriptor expressing the equivalent concept. For example, at the entries for the descriptors ACCIDENTS, AORTA, and ARM, the references read:

  ACCIDENTS/prevention & control see ACCIDENT PREVENTION

  AORTA/radiography see AORTOGRAPHY

  ARM/injuries see ARM INJURIES

All descriptors can be used for online searching. Most are used for both indexing and cataloging. In the indexing process, indexers assign as many descriptors as are needed to accurately characterize the content of a journal article. Of the 10 to 12 usually assigned, those representing the most significant points are identified with an asterisk in the online citation. It is under those descriptors that the citation have been previously located in Index Medicus. The remaining descriptors are used to identify concepts which have also been discussed in the item, but that are not the primary topics.

In the alphabetic listing in this publication, each descriptor is followed by one or more alphanumeric expressions (tree numbers) that indicate where in the Tree Structures the term is to be found. A plus sign following a tree number in the Alphabetic List indicates there are more specific descriptors in the Tree Structures at that number under that descriptor.