Thanks again for the reply.
There are a variety of possible causes for dizziness. If the symptom is pretty consistent and not going away completely, then one of the more concerning possibilities could be a stroke (especially if the symptom started suddenly). A stroke normally might also produce numbness or weakness on one side of the body or slurred speech, but not always. The fact that the dizziness is pretty constant makes me concerned enough that he should see a doctor about this if the symptoms are persisting (an MRI of the brain could help diagnose this).
Another possible cause which is usually less dangerous is a condition called labyrinthitis, which sometimes is caused by a virus, and also could possibly produce muscle aching. This is much more difficult to diagnose.
If the dizziness feels like he is about to pass out (doesn't sound like it), then one would need to make sure that his blood pressure isn't getting too low. I think this is less likely than either of the first 2 possibilities.
Therefore, I would recommend that he see his doctor again in the near future if the symptoms are persisting, to make sure this isn't a stroke he's dealing with.
Good luck. Please let me know if there are any other questions. If you have found this helpful, please click on ACCEPT so that I may be reimbursed for the time taken to answer this question.