Hypoparathyroidism is a condition where the parathyroid glands produce insufficient amounts of parathyroid hormone (PTH), which is crucial for regulating calcium and phosphorus levels in the body. The causes of hypoparathyroidism can be diverse, but they generally fall into several main categories: surgical injury, autoimmune destruction, genetic factors, and other less common causes.
The most frequent cause of hypoparathyroidism is accidental damage or removal of the parathyroid glands during neck surgeries, especially thyroidectomy (removal of the thyroid gland) or surgery on nearby structures. Because these tiny glands are located close to the thyroid gland and other neck tissues, they can be inadvertently injured or removed during such procedures. This leads to a sudden drop in PTH production and subsequent low calcium levels in the blood. Postoperative hypoparathyroidism is considered a significant clinical challenge due to its frequency after these surgeries[2][4][5].
Another important cause involves autoimmune processes where the body’s immune system mistakenly attacks its own parathyroid tissue. This autoimmune destruction reduces or eliminates PTH secretion over time. Autoimmune hypoparathyroidism may occur alone or as part of broader autoimmune syndromes affecting multiple endocrine organs.
Genetic mutations also play a role in some cases, particularly when hypoparathyroidism appears early in life without any history of surgery or obvious injury. These inherited forms can result from mutations affecting development or function of the parathyroid glands themselves.
Certain rare conditions and treatments may induce hypoparathyroidism as well. For example, immune checkpoint inhibitors—drugs used in cancer therapy—have been reported to cause various endocrine side effects including rare cases of hypoparathyroidism by triggering inflammation that damages hormone-producing tissues[3]. Other less common causes include infiltration by diseases such as hemochromatosis (iron overload), radiation damage from cancer treatments targeting head and neck areas, infections that affect glandular tissue directly, and congenital absence or malformation of parathyroids.
In summary:
– **Surgical injury**: Most common; accidental removal/damage during thyroidectomy or neck surgery.
– **Autoimmune destruction**: Immune system attacks parathyroids.
– **Genetic causes**: Inherited defects leading to underdeveloped/absent glands.
– **Drug-induced/iatrogenic**: Immune therapies causing inflammation; radiation exposure.
– **Other rare causes**: Infiltrative diseases like hemochromatosis; infections; congenital absence.
Understanding what triggers this hormone deficiency helps guide treatment strategies aimed at restoring calcium balance through supplementation since direct replacement with PTH itself remains limited outside specialized settings.
