Parathyroid osteodystrophy is a headache for two people, and many people miss the best time for treatment because they do not understand its diagnosis, thus causing serious consequences. Here, we will learn what is the diagnosis of parathyroid osteodystrophy. How is parathyroid osteodystrophy diagnosed? The diagnosis of hyperparathyroidism is based on: ① high blood calcium ② low blood phosphorus and ③ subperiosteal bone resorption at the tip of the terminal phalanges. However, many diseases need to be differentiated, including multiple myeloma, osteoporosis, deformational osteitis, and even metastatic tumors. The diagnosis of hyperparathyroidism by puncture is not helpful, as it can only exclude some diseases, and sometimes the puncture can be confusing. Because giant cells can be found in the puncture material, it is sometimes misdiagnosed as multiple giant cell tumors of bone, or even as malignant giant cell tumors of bone because the lesions keep appearing. It is possible to distinguish secondary hyperparathyroidism from secondary hyperparathyroidism based on the level of blood phosphorus, but it is difficult to diagnose a third type of hyperparathyroidism, and the diagnosis can only be made based on the entire history of development. Localization and characterization of the parathyroid lesions are even more difficult. Diagnosis can be made with the use of isotope selenography and selective arteriography, as well as with the use of transhypoparathyroidal catheterization and determination of parathyroid hormone levels in the inferior thyroid vein. These are the diagnostic methods of parathyroid osteodystrophy. Through these diagnostic methods, we can diagnose whether we are suffering from parathyroid osteodystrophy in a timely manner, therefore, once we find out that our body has symptoms related to parathyroid osteodystrophy, we must go to a regular hospital for relevant diagnosis in a timely manner.