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Searching PubMed Using MeSH Search Tags

Subheadings [SH]

  • A list of subheadings can be found in PubMed's Help.
  • Definitions for the subheadings (also called qualifiers) can be found on the MeSH Web site.
  • MeSH specialists and indexers determine which subheadings may be used in combination with each MeSH heading.   These combinations may change over time.
  • For searching, attach subheadings to MeSH headings using the format: MeSH heading/subheading.  
  • Two-letter abbreviations for subheadings or the full subheading name may be used.


thromboembolism/pc [mh]
thromboembolism/prevention and control [mh]
toes/in [majr]
toes/injuries [majr]

Only one subheading may be attached to a MeSH heading at a time.   To attach multiple subheadings, combine each MeSH/subheading combination with the OR Boolean operator or use the MeSH Database, which allows multiple subheadings to be selected.


To search for citations where the main topics are about the prevention and control or diagnosis of thromboembolism, enter:

thromboembolism/pc [majr] OR thromboembolism/di [majr]

For a MeSH/subheading combination, PubMed always explodes the MeSH term and also searches the subheading and its grouping if there is one.   You cannot explode a MeSH heading and not also explode the attached subheading.



Retrieves citations indexed with any of the polysaccharides with any of these subheadings:   

ae (adverse effects)
po (poisoning)
to (toxicity)

Note:   polysaccharides/ae [mh:noexp] turns off both the MeSH heading explosion and the subheading explosion.

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