Hypercalcemia causes and symptoms
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Causes of Hypercalcemia: Primary Hyperparathyroidism, Malignancy, and Other Factors
The most common causes of hypercalcemia are primary hyperparathyroidism (PHPT) and malignancy, accounting for over 90% of cases in adults. PHPT is characterized by excessive secretion of parathyroid hormone, while malignancy-related hypercalcemia often results from tumor production of parathyroid hormone-related protein (PTHrP), bone metastases, or ectopic PTH secretion. Other less frequent causes include vitamin D intoxication, granulomatous diseases (such as sarcoidosis), certain endocrinopathies (like thyroid disease), immobilization, genetic disorders, and medications (notably thiazide diuretics, calcium or vitamin D supplements, and some cancer therapies). Rare causes include sodium-glucose cotransporter 2 inhibitors, immune checkpoint inhibitors, denosumab discontinuation, SARS-CoV-2 infection, ketogenic diets, and extreme exercise, but these account for less than 1% of cases 1235+4 MORE.
In children, hypercalcemia can be either PTH-dependent or PTH-independent. PTH-independent causes are more common in pediatric populations and include hypervitaminosis, granulomatous disorders, endocrinopathies, and congenital syndromes such as idiopathic infantile hypercalcemia and Williams syndrome. PTH-dependent hypercalcemia in children is usually due to parathyroid tumors or hereditary syndromes .
Symptoms of Hypercalcemia: Mild, Moderate, and Severe Presentations
Symptoms of hypercalcemia depend on both the severity and the speed of onset. Mild hypercalcemia is often asymptomatic or may cause nonspecific symptoms such as fatigue and constipation in about 20% of people. Moderate to severe hypercalcemia, especially if it develops rapidly, can lead to more pronounced symptoms including nausea, vomiting, dehydration, confusion, somnolence, and even coma. Chronic or slowly developing hypercalcemia may present with fatigue, kidney stones (nephrolithiasis), and gastrointestinal complaints 1235+2 MORE.
Neuropsychiatric symptoms (such as confusion, depression, and changes in mental state) and gastrointestinal symptoms (like nausea, vomiting, and abdominal pain) are particularly common in severe cases. In children, symptoms can include hypotonia, poor feeding, vomiting, constipation, abdominal pain, lethargy, polyuria, dehydration, failure to thrive, seizures, and psychiatric symptoms in older children and adolescents. Severe, untreated hypercalcemia can result in renal failure, pancreatitis, and reduced consciousness 2348+2 MORE.
Diagnostic Approach: Identifying the Underlying Cause
Diagnosis of hypercalcemia starts with measuring serum calcium and confirming the result with albumin-corrected or ionized calcium levels. The most important initial test is serum intact parathyroid hormone (PTH), which helps distinguish between PTH-dependent and PTH-independent causes. Elevated or normal PTH suggests PHPT, while suppressed PTH points to other causes such as malignancy or vitamin D intoxication 356.
Conclusion
Hypercalcemia is most commonly caused by primary hyperparathyroidism and malignancy, but can also result from a variety of other conditions and medications. Symptoms range from mild or absent in chronic, low-level cases to severe neuropsychiatric and gastrointestinal disturbances in acute or high-level cases. Early recognition and identification of the underlying cause are crucial for effective management and prevention of complications 1234+6 MORE.
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