Disease Description (Causes and Symptoms)
- Definition summary: A condition in which excess parathyroid hormone (PTH) secreted by the parathyroid glands increases the concentration of calcium in the blood (hypercalcemia).
- Main causes (in order of priority):
- Solitary parathyroid adenoma (benign tumor) — most common
- Hyperplasia of the parathyroid glands overall (multiple or typical hyperplasia)
- Parathyroid cancer (rare)
- Hereditary causes (familial primary hyperparathyroidism, MEN syndromes, etc.)
- Secondary and tertiary hyperparathyroidism occurring in chronic kidney failure (related to kidney disease)
- Pathophysiology: Excess PTH increases the release of calcium from bones, increases calcium reabsorption in the kidneys, and decreases phosphate removal → increased blood calcium levels. Calcium absorption in the intestines may also increase.
- Main symptoms (many patients are asymptomatic):
- Digestive: nausea, vomiting, loss of appetite, constipation
- Kidney/urinary tract: kidney stones (urinary tract stones), decreased kidney function
- Skeletal/muscular: osteoporosis, bone pain, muscle weakness, fatigue
- Neuropsychiatric: depressed mood, decreased memory, confusion
- Other: excessive sweating (hands, feet, and armpits), decreased skin elasticity, hypertension
- Clinical variation: A long-term asymptomatic course is possible. Rarely, an acute hypercalcemic crisis may occur (dehydration, decreased consciousness, coma).
Treatment Methods
- Observation (for asymptomatic or mild cases)
- Regular follow-up: serum total/ionized calcium, PTH, kidney function, 24-hour urinary calcium, and bone mineral density (DEXA). Record changes in lifestyle and symptoms.
- Surgical treatment (definitive treatment)
- Indications: symptomatic disease (kidney stones, osteoporosis, muscle or neurological symptoms), age ≤50 years, serum calcium >1 mg/dL above the upper limit of normal, bone mineral density T-score ≤ −2.5 or a history of fracture, or decreased kidney function (e.g., decreased glomerular filtration rate, kidney stones/nephrocalcinosis).
- Surgical method: If localized by ultrasound, sestamibi, 4D-CT, or other methods, minimally invasive parathyroidectomy (MIP) is performed. Intraoperative PTH measurement is used to confirm complete removal.
- Postoperative complications: temporary or permanent hypocalcemia (especially hungry bone syndrome), recurrent disease, or residual lesions.
- Drug treatment (when surgery is not possible or as alternative therapy)
- Cinacalcet (such as Calcimex): intended to lower serum calcium, particularly in patients with predominant hypercalcemia or when surgery is not possible. Its effect on improving PTH is limited.
- Osteoporosis management: bisphosphonates (alendronate, zoledronate) — improve bone mineral density. (Bisphosphonates are intended to protect the bones rather than lower blood calcium over the long term.)
- Vitamin D deficiency supplementation: if vitamin D deficiency is present, supplement cautiously, taking into account the possibility of inducing an increase in calcium.
- Hypercalcemic crisis (emergency)
- Immediate treatment: aggressive IV fluids (normal saline); if necessary, promote calcium excretion with a loop diuretic (furosemide).
- Fast-acting agent: calcitonin (temporary lowering of calcium)
- Sustained inhibitor: IV bisphosphonates (such as zoledronate) — inhibit bone resorption; it takes several days for the effect to occur
- Steroids: consider when related to vitamin D excess or overhydration
- Last resort: dialysis in cases of decreased kidney function or lack of response to medication
- Lifestyle management and precautions
- Prevent dehydration by drinking sufficient fluids
- Do not excessively consume high-calcium foods or supplements (calcium tablets)
- Use caution with thiazide diuretics, as they can increase blood calcium
- Stop smoking, exercise regularly, and maintain a balance of calcium and vitamin D as directed by a doctor
Checklist Before an Outpatient Visit (What to Bring and Sample Questions)
- Items/test records to bring
- Recent blood test results: total and ionized calcium, PTH, phosphate, creatinine (kidney function), albumin (for calculating corrected values), and 25(OH) vitamin D
- 24-hour urinary calcium test results, if available
- Bone mineral density test (DEXA) results, if available
- Results of recent imaging (neck ultrasound, parathyroid sestamibi, CT, etc.), if available
- List of all medications and supplements currently being taken (especially calcium supplements, vitamin D, and diuretics)
- Record of changes in symptoms such as a history of kidney stones, fractures, muscle weakness, or psychiatric symptoms
- Information to tell the doctor first during the outpatient visit
- Any recent dehydration or severe vomiting, and whether medications have been changed
- Family history (MEN, familial hypercalcemia, etc.) or any previous neck surgery
Examples of General Questions to Ask the Doctor
- “Are my current blood calcium and PTH levels at a level that requires surgery?”
- “What are the side effects and expected benefits of this medication (e.g., cinacalcet)?”
- “What risks are there if I do not have surgery and instead undergo observation? How often should follow-up tests be performed?”
- “What treatments and lifestyle habits do you recommend to reduce the risk of fractures?”
Disease-specific questions (examples)
- “Based on my test results (calcium, PTH, 24-hour urinary calcium, etc.), how do you determine whether the cause is primary or secondary/tertiary?”
- “If surgery is recommended, what will the surgical method (minimally invasive vs. total parathyroidectomy), hospital stay, and recovery process be like? What should I prepare to reduce the risk of ‘hungry bone syndrome’?”
Key Points Commonly Used in Diagnosis and Treatment
- Diagnostic key point: If PTH is “abnormally elevated or inappropriately high despite being within the normal range” in the presence of hypercalcemia, hyperparathyroidism is suspected. To differentiate familial hypocalciuric hypercalcemia (FHH), 24-hour urinary calcium should be checked and genetic testing considered if necessary.
- Prognosis: With appropriate surgery, adenomas have a high cure rate. Many asymptomatic patients can be managed stably with periodic monitoring. However, if left untreated, kidney and skeletal complications may occur, and, rarely, cardiovascular risk may increase.