There may be several reasons why MedlinePlus does not point to a familiar or popular Web site.

• MedlinePlus is not a list of every Web page on health, but is a selected list of authoritative resources.
  
  
• MedlinePlus uses quality guidelines to evaluate Web sites. MedlinePlus tries to ensure that the information it links to is authoritative, accurate, up-to-date, educational and available at no charge.
  
  
• MedlinePlus does not point to multiple Web sites that contain the same information, even if different organizations, associations, companies or entities are responsible for their content.