Hypoparathyroidism. Often occurs as a result (unintended) of parathyroid or thyroid surgery. It can take years for symptoms to develop. Hypoparathyroidism can develop after thyroidectomy due to damage of the gland blood supply, post-op swelling, or fibrosis. Manifests as low serum calcium levels. And, with hypocalcemia can come cramps, fatigue, hyperirritabilty, depression, anxiety, nonspecific ECG changes, increases in intracranial pressure, and longer Q-T intervals.