Dizziness is common in Parkinson's. A recent study broke down the causes like this: "57 (38%) of the dizzy patients had orthostatic hypotension [OH]; 12 patients (8%) had a classical but previously unrecognized benign paroxysmal positional vertigo [BPPV]. A further four patients (3%) had a more atypical presentation of benign paroxysmal positional vertigo." This leaves about half the dizzy Parkinson's patients with unknown cause. bit.ly/2GnpphJ
You can actually do the checks for OH and BPPV at home if you are so inclined. Checking for orthostatic hypotension requires a good blood-pressure cuff and measuring blood pressure both lying down and standing. Orthostatic hypotension is defined as a drop of 20 points of the systolic blood pressure reading. Systolic is the higher of the two blood pressure numbers.
Test for BPPV involves doing something called the "Dix–Hallpike maneuver". This is a short sequence of motions as shown in these YouTube videos. bit.ly/2GnpGBh
Orthostatic hypotension is frequently caused by dopamine agonists (DAs) but can also be caused by Parkinson's itself and some other Parkinson's medications. If a dopamine agonist is suspected it must be tapered if it has been used for any length of time. Orthostatic hypotension is not true dizziness but rather "lightheadedness".
The remedy for BPPV is the Epley maneuver as shown in these YouTube videos bit.ly/2GnpGBh Afterwards the patient is supposed keep the head upright for the next 48 hours, however, this study showed it did not make much difference. bit.ly/2DIfBgp
Here is a site with a good list of the various vestibular disorders any of which can cause dizziness: bit.ly/19SEKyv
For general symptomatic relief of true dizziness meclizine helps a bit. Scopolamine patches are highly effective but they require a prescription.
If you have experienced dizziness, tinnitus or hearing loss in connection with PD this is a good place to tell your story.