Mavericks Using Up All Available Memory
Try opening Terminal and typing in: 
sudo purge

or you can try Memory Clean at 
https://itunes.apple.com/us/app/memory-clean/id451444120?mt=12

BTW: It would be beneficial to post screenshots or use EtreCheck (created by an Apple Support Community User) and copy and paste the results. Etrecheck can be found at http://www.etresoft.com/etrecheck