I Have Dizziness All The Time. I Have Had A

I have dizziness all the time. I have had a number of tests with no diagnosis. The days that it is the worst I have a constant runny nose, pressure in my face and sometimes a dull headache. I think it is sinus but dizziness is not listed as a side effect. Any ideas on what it could be. I have had this for at least 2-3 years but it seems to be getting worse.