What Is Vertigo More Condition_symptoms What Is The Possible Cause Of Vertigo Upon Waking?

What is the possible cause of vertigo upon waking? - what is vertigo more condition_symptoms

My father complained of dizziness, when he wakes up in the morning. He is in his late 40s and has no other symptoms. He said he was a doctor to see if it was a condition of the inner ear and the doctor said no. Vertigo does not change when changing position and will be taken from time to time throughout the day and accompanied by trembling of the hands of this. Who knows what could be causing this? I'm trying to see him to another doctor. Any help would be great.