Question for Jonna Radhakrishna Dr

Good afternoon Doc. I am currently living in the Cayman Island for the pass few months. I went to the Doctor here and did an entire bloodwork,when the results came back twice my calcium level was high. I got a referral to do a scan to check my parathyroid glands,after conducting the scan no evidence of a parythroid adenomia was found. What could be causing me to have a high calcium level?