I can answer one of them: Secondary hyperparathyroidism is when the parathyroid glands in your neck produce too much parathyroid hormone (PTH) because your calcium levels are too low. This is something I'm dealing with and have just started taking meds to control it. I got started on Hectorol last week to work on getting the levels balanced back out (oh joy, yet another pill to take in the morning - I rattle for half an hour as it is
) In the long run, it can cause your system to pull calcium from your bones making them brittle and prone to breaking.
HTH