Hyperparathyroidism
Hyperparathyroidism
Introduction
The parathyroid glands are small endocrine organs located behind the thyroid gland. In hyperparathyroidism, excessive amounts of parathyroid hormone (PTH) are produced.
Role of Parathyroid Glands
PTH is crucial for regulating calcium and phosphorus levels in the blood, which is vital for nerve cells, muscles, and bones.
Hyperparathyroidism is classified into primary and secondary types:
Primary hyperparathyroidism occurs when one or more enlarged glands produce excess PTH, leading to high blood calcium levels. Surgery is the most common treatment.
Secondary hyperparathyroidism results from an underlying condition, such as kidney disease, that causes low blood calcium (hypocalcemia).
Symptoms
Primary hyperparathyroidism is often diagnosed before symptoms appear during routine blood tests showing elevated calcium levels. When symptoms do occur, they result from damage to various tissues and organs:
Weak or brittle bones (osteoporosis)
Kidney stones
Frequent urination
Abdominal pain
Fatigue and general weakness
Depression or memory issues
Bone and joint pain
Frequent infections
Nausea, vomiting, or loss of appetite
Causes
Primary Hyperparathyroidism
A benign tumor (adenoma)
Enlargement of two or more parathyroid glands (hyperplasia)
Rarely, a malignant tumor of the gland
Secondary Hyperparathyroidism
Calcium deficiency
Vitamin D deficiency
Chronic kidney failure
Risk Factors
Menopause
Long-term calcium or vitamin D deficiency
Genetic disorders, such as Multiple Endocrine Neoplasia (MEN type 1)
Radiation therapy to the neck
Use of lithium
Complications
Osteoporosis – increased risk of fractures
Kidney stones – due to excessive calcium
Cardiovascular disease – such as high blood pressure
Neonatal hypoparathyroidism – untreated maternal hyperparathyroidism can lead to critically low calcium levels in newborns
Diagnosis
Laboratory Tests
If an elevated calcium level is detected, a fasting blood test should confirm the finding.
Key tests include:
Corrected calcium and PTH levels
24-hour urine calcium excretion
Phosphorus levels
Vitamin D levels
Additional Diagnostic Tests
Bone density scan (DXA) – to assess osteoporosis
Kidney imaging – to check for kidney stones
Parathyroid gland scan using sestamibi – a radioactive substance that accumulates in overactive parathyroid tissue
Ultrasound – uses sound waves to visualize parathyroid glands
Treatment Options
Monitoring (Observation Approach)
Your doctor may recommend a wait-and-see approach if:
Calcium levels are only mildly elevated
Kidney function is normal and there is no history of kidney stones
Bone density is within or near the normal range
You have no significant symptoms
If monitoring is chosen, regular blood tests for calcium and bone density checks are required.
Surgery
Surgical removal of the overactive parathyroid gland(s) is the only definitive cure for primary hyperparathyroidism.
If only one gland is affected, it is removed.
If all four glands are affected, three are removed completely, and part of the fourth is left intact to maintain function.
Surgical complications are rare but may include:
Vocal cord damage
Long-term low calcium levels (hypocalcemia) requiring calcium and vitamin D supplements
Medications
Calcimimetics (e.g., Cinacalcet/Sensipar) – mimic blood calcium levels and reduce PTH production
Bisphosphonates – used to treat osteoporosis and lower high calcium levels
Lifestyle & Prevention Tips
Increase fluid intake – helps prevent kidney stones
Regular exercise – supports bone health
Avoid smoking – reduces the risk of bone loss
Consume calcium-rich foods – adequate calcium intake helps regulate PTH levels
Ensure sufficient vitamin D intake
Avoid medications that raise calcium levels, such as certain diuretics and lithium