select db_name(dbid) as DataBaseName , count(dbid) as No_Of_Connections , loginame as LoginName from sys.sysprocesses
where dbid > 0
group by dbid,loginame
By frequently running this query. You observed that the number of connections opened is high then there exist bug in your application
which didn't closed the opened connections. Stop the web application who uses that database and start over, system would run first
and later it suffers slow response then stops responding. In this situation you need to fix your application and not to blame SQL server.