Abstract
Introduction: Hypoparathyroidism is considered uncommon problem that is described by decreased serum calcium, elevated serum phosphorus, and insufficient production of parathyroid hormone (PTH). The epidemiology of hypoparathyroidism has been studied very well, with many studies quantitating aspects of the disease not previously understood. Pseudohypoparathyroidism, a disorder of PTH resistance, is very uncommon disease described by similarly abnormal mineral biochemical abnormalities, however with elevated circulating levels of PTH. Surgically, hypoparathyroidism can be categorized into primary hypoparathyroidism because of intrinsic defects within the parathyroid glands primarily due to genetic causes, and the much more common secondary or acquired forms due to causes that ablate, weaken or destroy parathyroid gland function. Secondary causes of hypoparathyroidism are by far the most common causes. While the diagnosis of hypoparathyroidism is often uncomplicated once serum calcium, phosphorus, and PTH levels are well-known, determining the cause of nonsurgical hypoparathyroidism is considered difficult. Aim of work: In this review, we will discuss types, manifestations, and causes of hypo parathyroidism.. Methodology: We did a systematic search for Types, manifestations, and causes of hypoparathyroidism using PubMed search engine (http://www.ncbi.nlm.nih.gov/) and Google Scholar search engine (https://scholar.google.com). All relevant studies were retrieved and discussed. We only included full articles. Conclusions: The recent developments have clarified some characteristics of the epidemiology and diagnosis of hypoparathyroidism. Postsurgical hypoparathyroidism is responsible for about 3/4 of all cases of known hypoparathyroidism. In patients undergoing anterior neck surgery, less than five percent will have permanent hypoparathyroidism, even though as many as fifty percent could develop transient hypoparathyroidism. The remaining cases of hypoparathyroidism are caused by autoimmune disease, metastatic disease, iron or copper overload, radiation therapy or radioactive iodine treatment, or a variety of rare genetic disorders. Complications of hypoparathyroidism are many including chronic kidney disease, kidney stones or nephrocalcinosis, seizures, posterior subcapsular cataracts, and intracerebral calcifications. The risk of infections may be higher in this disorder. Cardiovascular disease, fractures, and malignancy do not appear to be increased, except for increased upper extremity fractures in nonsurgical hypoparathyroidism. Gastrointestinal cancers could be reduced in hypoparathyroidism. The diagnosis of the genetic causes of hypoparathyroidism and pseudohypoparathyroidism has been significantly clarified in recent years, with recognition of an increasing variety of different genes affecting parathyroid gland differentiation and function. Evaluation for most of the recognized mutations can now be performed by research or commercially available genetic testing.