Restore from backup.
If your database is FULL Recovery Model then make a TAIL Log Backup first.
Make a trial restore to a different server. If you are using FULL and have all the Log backups since the last Full backup then the chances are high that you will have zero data loss. If this has been going on for a while then you may have to go back to an earlier FULL backup (and restore many more Log backup files!)
Either way, find what caused the problem first (duff memory or disk controller) and get that fixed - otherwise its just going to happen again.
Suggest you post whatever messages you get from DBCC CHECKDB so folk here can make suggestions.
DBCC CHECKDB WITH NO_INFOMSGS, ALL_ERRORMSGS