Hypercalcemia
Evaluation & Treatment — Houston, TX
Elevated calcium in the blood — hypercalcemia — is most commonly caused by primary hyperparathyroidism or malignancy. Our board-certified endocrinologists in Houston provide expert evaluation to identify the underlying cause and guide the right treatment.
Quick Facts
What Causes High Calcium?
Hypercalcemia means the calcium level in your blood is above normal. It is most often discovered incidentally on routine blood work — many patients have no symptoms at first. However, persistently elevated calcium can cause significant problems and always warrants evaluation.
Over 90% of hypercalcemia cases are caused by either primary hyperparathyroidism (overactive parathyroid glands) or malignancy (cancer releasing calcium-elevating substances). Other causes include Vitamin D toxicity, granulomatous diseases such as sarcoidosis, certain medications, and immobilization.
Endocrinologists are the right specialists to evaluate hypercalcemia because most causes are hormonal or metabolic — and because getting the diagnosis right determines the entire treatment path.
Kidney Stones
Excess calcium filtered through kidneys increases stone risk
Bone Pain
PTH-driven bone resorption causes pain and fracture risk
GI Symptoms
Nausea, constipation, and abdominal pain are common
Fatigue & Brain Fog
Cognitive symptoms, depression, and low energy
Excessive Thirst & Urination
Calcium interferes with kidney's ability to concentrate urine
Cardiac Effects
Severe hypercalcemia can cause arrhythmias and hypertension
How We Work Up Hypercalcemia
Confirm & Characterize the Elevation
We verify the calcium elevation with repeat testing, measure both total and ionized calcium, and assess the albumin level to calculate corrected calcium. We also review all medications and supplements that can raise calcium.
PTH-Directed Workup
The single most important test is the intact PTH level. An elevated or inappropriately normal PTH in the setting of high calcium confirms primary hyperparathyroidism. A suppressed PTH points toward malignancy, Vitamin D excess, or other non-PTH-mediated causes — each of which requires a distinct workup.
Extended Evaluation Based on Cause
Depending on the PTH result, we may add 24-hour urine calcium and creatinine (to rule out familial hypocalciuric hypercalcemia), PTHrP, Vitamin D levels (25-OH and 1,25-OH), ACE level, SPEP, and imaging studies including parathyroid ultrasound or sestamibi scan.
Treatment & Referral Coordination
Primary hyperparathyroidism causing symptomatic hypercalcemia is often best treated surgically. We provide medical optimization pre-surgery, coordinate with endocrine surgeons, and manage patients who are not surgical candidates. Non-PTH causes receive targeted treatment specific to their etiology.
Physicians Who Evaluate Hypercalcemia
Related Education Resources
Hypercalcemia FAQ
My calcium was slightly elevated on a routine lab — do I need to worry?
Mildly elevated calcium found incidentally should always be confirmed with repeat testing and PTH measurement. Many cases of mild primary hyperparathyroidism are discovered this way. While some patients can be monitored without immediate intervention, others benefit from surgical evaluation — and only an endocrinologist can guide that decision properly.
What is familial hypocalciuric hypercalcemia (FHH) and why does it matter?
FHH is a benign genetic condition that causes mild hypercalcemia but does NOT require surgery. It can mimic primary hyperparathyroidism on standard testing. A 24-hour urine calcium-to-creatinine ratio helps distinguish FHH from true hyperparathyroidism — an important distinction that prevents unnecessary surgery.
If I have primary hyperparathyroidism, do I definitely need surgery?
Not necessarily. Surgery (parathyroidectomy) is recommended for patients with symptoms, significantly elevated calcium, kidney stones, osteoporosis, or young age. Patients who don't meet these criteria may be monitored conservatively. Our endocrinologists use current guidelines to help you make the right decision for your situation.
Can too much calcium or Vitamin D supplementation cause hypercalcemia?
Yes. Vitamin D toxicity from excessive supplementation is an increasingly recognized cause. We see this more commonly now with widespread high-dose Vitamin D use. If you are taking large doses of Vitamin D, mentioning this to your physician is important — and routine monitoring of calcium and Vitamin D levels is advisable.