Hello i really hope someone can help I had a left

Patient: Hello i really hope someone can helpI had a left ear mastoidectomy in november last year (2014) ever since then i have suffered from bad dizziness. It has got worse over the last few months to the point that i now feel extreamly dizzy all the time.I have collapsed a couple of times as well.My questions are:1. What could be the cause of this?2. I have been refered to hospital for balance tests what will these intail?many thanksCraig Souter

Symptoms: Dizziness