Info Nuggets

Hungry bones: The post-parathyroidectomy calcium crisis

TNS

Chandigarh, Updated At : 04:37 PM Jul 18, 2025 IST

Hungry bone syndrome (HBS)

Introduction (brief overview)

Hungry bone syndrome (HBS) is a clinical condition characterised by severe, prolonged hypocalcemia (low blood calcium levels) that occurs after parathyroidectomy (surgical removal of the parathyroid gland), especially in patients with severe hyperparathyroidism.

After the removal of the overactive parathyroid gland, bones — previously demineralised due to excess parathyroid hormone (PTH) — suddenly begin to rapidly absorb calcium, phosphate and magnesium to rebuild bone mass. This causes a sudden drop in blood calcium levels, leading to symptoms of hypocalcemia.

Causes

Parathyroidectomy in patients with:

Primary hyperparathyroidism (usually due to parathyroid adenoma)
Secondary hyperparathyroidism (common in chronic kidney disease)

Long-standing high PTH levels cause:

Bone resorption (calcium released from bones)
Osteitis fibrosa cystica (weakened bones)
Post-surgery, sudden withdrawal of PTH causes increased bone uptake of calcium, leading to HBS.

Clinical features/symptoms

Muscle cramps
Numbness, tingling
Seizures
Cardiac arrhythmias (in severe cases)

Diagnosis

Low serum calcium
Low magnesium and phosphate
High alkaline phosphatase
Normal or low PTH post-surgery

Management & Cure

Preventive care: Identify high-risk patients preoperatively (e.g. CKD, severe hyperparathyroidism)

Treatment:

Calcium supplementation (oral/IV)
Vitamin D analogues (e.g. calcitriol)
Magnesium replacement (if deficient)
Monitoring:
Regular monitoring of electrolytes post-surgery

Relevance for UPSC

GS Paper III – Science and technology/health and diseases
Prelims – Conceptual understanding of medical syndromes, especially in context of endocrine disorders
Mains (GS II / III) – Can be used in health-related answers, especially regarding non-communicable diseases or surgical complications

Sample question types for UPSC:

Prelims (objective)

Q. Hungry Bone Syndrome is associated with which of the following glands?

A) Thyroid

B) Adrenal

C) Parathyroid ✅

D) Pituitary

Mains (short note/GS III – science & tech)

Q. What is Hungry Bone Syndrome? Briefly explain its pathophysiology and management. (Answer in 150 words)

Info Nuggets

Ravneet Kaur

TNS

Hungry bone syndrome (HBS)

Introduction (brief overview)

Causes

Clinical features/symptoms

Diagnosis

Management & Cure

Relevance for UPSC

Sample question types for UPSC:

Live Matches

Info Nuggets

Ravneet Kaur

TNS

Hungry bone syndrome (HBS)

Introduction (brief overview)

Causes

Clinical features/symptoms

Diagnosis

Management & Cure

Relevance for UPSC

Sample question types for UPSC:

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