I have two cysts on my thyroid, diagnosed with osteopenia and have had three unexplained rib fractures. hyperparathyroidism? do i need to get checked?

Yes: Get in to see your doc. Ask about PTH/parathyroid hormone level. It is a simple blood draw, can be added on to other labs. Will answer the question. Take a friend or family with you to appointment to help with questions and answers. Be well. Parathyroid glands are near your thyroid, usually need nuclear scans to detect on imaging. Only if, PTH level is up.

Broken ribs : A 43 yo male shouldn't have rib fractures without a history of significant chest trauma. Your bones are likely osteopenic or osteoporotic. This needs a dexa scan. Hyperparathyroidism is a possible explanation for thus. I would recommend paired calcium, ionized calcium, and intact PTH at a minimum be drawn. If these come back elevated, then get referred to a surgeon to order their preferred imaging