PubMed's MeSH terms will help you find focused results when searching a subject that may have many alternate names. By using terms from the MeSH thesaurus, all articles on a given topic can be found regardless of the terminology used by authors. MeSh can lead to finding terms not commonly known or used and allows users to search complex medical concepts using a single term without the need to type in long lists of synonyms.
Using the NLM MeSH Browser:
"Main Headings" (Descriptors): the MeSH terms
"Qualifiers" (Subheadings): aspects of a MeSH term
"Supplementary Concepts": not part of the controlled vocabulary
"Scope Note": information/definition about the term