ICPSR (Inter-university Consortium for Political and Social Research)
Data archive of more than 500,000 files of research in the social sciences (U.S. & International data). Health data includes health interview surveys, substance abuse data, lifestyle, access to services, poll results, physician surveys, etc. Note that some health data is restricted-use (requires specific approval for access) to preserve confidentiality.
Some data files may be analyzed online. To download files or analyze online you must create your own login. For files requiring specialized software, check with your departments for access