 This video will teach you how to search in the PubMed database using MESH, the Medical Subject Heading Index from the National Library of Medicine. Scroll down below the basic PubMed search box to the Explore MESH database link on the right hand bottom side of the screen. Click on it. You are now in the MESH search term screen. This helps you find controlled MESH subject terms that PubMed uses to organize its articles. This can save you time by increasing the precision of your searches. I'm going to search for different ways to describe lung diseases. I'll enter lung diseases in the MESH box. Click Search or hit Enter after that. Authorized MESH subject headings for lung diseases are listed on this results page along with a scope note describing each term. I'm going to search on Anthroposis. Click on the check box. Then click the Add to Search Builder button on the right hand side of the screen. The term is inserted into the PubMed search builder box. You can also add subheadings on this search. Click on the blue hyperlinked subject term. Scrolling down we can see the subheadings along with the MESH hierarchy describing broader and narrower terms. You can see how MESH is organized into a hierarchy at the bottom of the page. Let's click the check box under Prevention and Control. And then just like before, we'll click the Add to Search Builder button on the search box on the right hand side of the screen. PubMed search builder adds that term to our search. We're now telling PubMed we want to search on the MESH terms Anthroposis and Prevention and Control. Click Search PubMed. Our results page shows very precise, very relevant 40 articles. Searching in PubMed using controlled MESH terms allows us to narrow the number of articles we need to look through while improving the relevance of our returns. This video has taught you how to search in PubMed using the National Library of Medicine's MESH Index of Terms. If you have further questions about how MESH terms can improve the precision of your search, contact one of our librarians.