Hyperparathyroidism Flashcards
What is hyperparathyroidism?
Hyperparathyroidism is a condition characterised by excessive secretion of parathyroid hormone (PTH), leading to hypercalcaemia and related symptoms.
What are the three types of hyperparathyroidism?
Primary, secondary, and tertiary hyperparathyroidism.
What is the cause of primary hyperparathyroidism?
It is caused by a hyperfunctioning parathyroid gland, typically due to a solitary adenoma, hyperplasia, or, rarely, parathyroid carcinoma.
What causes secondary hyperparathyroidism?
It occurs due to chronic hypocalcaemia, often secondary to vitamin D deficiency or chronic kidney disease.
What is tertiary hyperparathyroidism?
It occurs after prolonged secondary hyperparathyroidism, where parathyroid glands become autonomous, secreting excessive PTH despite normal calcium levels.
What are the main symptoms of hyperparathyroidism?
Fatigue, weakness, bone pain, depression, constipation, kidney stones, and polyuria.
What are the “bones, stones, abdominal groans, and psychic moans”?
A mnemonic for the symptoms of hyperparathyroidism: bone pain, kidney stones, abdominal discomfort, and psychological disturbances like depression.
What is the role of PTH in calcium regulation?
PTH increases calcium levels by promoting bone resorption, increasing calcium absorption in the gut (via vitamin D), and reducing renal calcium excretion.
What is the pathophysiology of primary hyperparathyroidism?
Excess PTH secretion leads to increased calcium release from bones, enhanced calcium absorption in the gut, and decreased renal calcium excretion.
How does chronic kidney disease lead to secondary hyperparathyroidism?
Reduced renal function decreases vitamin D activation and calcium reabsorption, leading to hypocalcaemia and compensatory PTH secretion.
What are the key biochemical findings in primary hyperparathyroidism?
Elevated calcium, low or normal phosphate, and raised PTH levels.
What are the biochemical findings in secondary hyperparathyroidism?
Low or normal calcium, high phosphate (in chronic kidney disease), and elevated PTH levels.
What investigations are used to diagnose hyperparathyroidism?
Serum calcium, phosphate, PTH levels, vitamin D levels, and renal function tests. Imaging may include ultrasound or sestamibi scan of the parathyroid glands.
What is the role of a sestamibi scan in hyperparathyroidism?
A sestamibi scan identifies hyperfunctioning parathyroid glands, particularly in primary hyperparathyroidism.
What is the main differential diagnosis for hyperparathyroidism?
Hypercalcaemia due to malignancy, vitamin D toxicity, sarcoidosis, or medications like thiazides.
How is primary hyperparathyroidism managed?
Definitive management involves surgical removal of the affected parathyroid gland(s).
What are the indications for parathyroidectomy in primary hyperparathyroidism?
Symptomatic hypercalcaemia, complications (e.g., fractures, kidney stones), or very high calcium levels.
How is secondary hyperparathyroidism managed?
Treat the underlying cause, such as correcting vitamin D deficiency, phosphate binders, or active vitamin D analogues in chronic kidney disease.
What is the treatment for tertiary hyperparathyroidism?
Parathyroidectomy is typically required, as the glands are autonomous and unresponsive to medical management.
What are the complications of untreated hyperparathyroidism?
Osteoporosis, fractures, kidney stones, nephrocalcinosis, and cardiovascular complications such as hypertension.
What lifestyle advice is given to patients with hyperparathyroidism?
Adequate hydration, avoiding excessive calcium or vitamin D intake, and regular monitoring of bone health and kidney function.
How does hyperparathyroidism affect bone density?
Increased PTH levels cause bone resorption, leading to reduced bone density and increased fracture risk.
What is the role of bisphosphonates in hyperparathyroidism management?
Bisphosphonates may be used to manage osteoporosis by reducing bone resorption in patients with hyperparathyroidism.
How does hyperparathyroidism cause kidney stones?
Hypercalcaemia increases calcium excretion in urine, predisposing to stone formation.
What are the clinical signs of hypercalcaemia?
Dehydration, polyuria, constipation, confusion, arrhythmias, and muscle weakness.
