PubVenn enables you to explore PubMed using venn diagrams. Enter any multi-term search above to see the relative size of the citation set for each term as well as how those sets interact.
For example, you can try simple searches such as smoking AND cancer or slightly more complex ones such as mosquito AND dengue AND caribbean.
Note: You can now use parantheses to group terms together in a search -- for example, depression AND (euthanasia OR assisted suicide)
Use the "expanded subjects" option to see the myriad of terms that PubMed translates your search into before it gets run, as with cancer [expanded] or heart disease [expanded]. Please note that due to the number of terms a search can get mapped to, the sets for expanded subjects can take a few seconds to render.