What are the symptoms of hypercalcemia (elevated calcium levels)?

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From the Guidelines

Hypercalcemia symptoms include polyuria, polydipsia, nausea, confusion, vomiting, abdominal pain, and myalgia, and can progress to severe dehydration, acute renal failure, mental status changes, bradycardia, and hypotension if left untreated, as noted in the study by 1. The severity of symptoms typically correlates with both calcium levels and how quickly they rise. Mild hypercalcemia may cause few or no symptoms, while severe hypercalcemia can lead to significant neurological symptoms like confusion, lethargy, and even coma. Gastrointestinal symptoms occur because calcium affects smooth muscle function and nerve conduction. Kidney-related symptoms develop as the body tries to eliminate excess calcium, leading to polyuria and potential kidney damage. The diagnostic evaluation includes measuring serum concentrations of intact parathyroid hormone (iPTH), parathyroid hormone-related protein (PTHrP), 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, calcium, albumin, magnesium, and phosphorus, as outlined in the study by 1. Some key points to consider when evaluating hypercalcemia symptoms include:

  • The patient's medical history, including the presence of lung cancer or other conditions that may contribute to hypercalcemia, as discussed in the study by 1.
  • The severity of symptoms and the rate at which they develop, as noted in the study by 1.
  • The results of laboratory tests, including serum calcium levels and other markers of bone and mineral metabolism, as outlined in the study by 1. Treatment of hypercalcemia typically involves hydration, bisphosphonates, and other medications, such as loop diuretics and glucocorticoids, as recommended in the study by 1. It is essential to seek medical attention promptly if symptoms of hypercalcemia occur, especially in individuals with risk factors like hyperparathyroidism, certain cancers, or medications that affect calcium levels, as untreated hypercalcemia can lead to serious complications, including kidney failure and cardiac arrest, as noted in the study by 1.

From the FDA Drug Label

Excessive release of calcium into the blood as bone is resorbed results in polyuria and gastrointestinal disturbances, with progressive dehydration and decreasing glomerular filtration rate

  • Symptoms of hypercalcemia include:
    • Polyuria (excessive urine production)
    • Gastrointestinal disturbances
    • Progressive dehydration
    • Decreasing glomerular filtration rate 2

From the Research

Symptoms of Hypercalcemia

The symptoms of hypercalcemia can vary depending on the severity of the condition. According to 3, 4, mild hypercalcemia is usually asymptomatic, but may be associated with constitutional symptoms such as:

  • Fatigue
  • Constipation Severe hypercalcemia, on the other hand, can cause:
  • Nausea
  • Vomiting
  • Dehydration
  • Confusion
  • Somnolence
  • Coma

Causes of Hypercalcemia

The two most common causes of hypercalcemia are:

  • Primary hyperparathyroidism (PHPT)
  • Malignancy Other causes of hypercalcemia include:
  • Granulomatous disease such as sarcoidosis
  • Endocrinopathies such as thyroid disease
  • Immobilization
  • Genetic disorders
  • Medications such as thiazide diuretics and supplements such as calcium, vitamin D, or vitamin A
  • Dehydration, which can be both a cause and a consequence of hypercalcemia, as seen in 5

Severity of Hypercalcemia

The severity of hypercalcemia can be classified based on the serum calcium level:

  • Mild hypercalcemia: total calcium of less than 12 mg/dL (<3 mmol/L) or ionized calcium of 5.6 to 8.0 mg/dL (1.4-2 mmol/L)
  • Severe hypercalcemia: total calcium of 14 mg/dL or greater (>3.5 mmol/L) or ionized calcium of 10 mg/dL or greater (≥2.5 mmol/L) As noted in 4, 6, severe hypercalcemia requires immediate medical attention and treatment.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Hypercalcemia: an evidence-based approach to clinical cases.

Iranian journal of kidney diseases, 2009

Research

Hypercalcemia: A Review.

JAMA, 2022

Research

Unusual Case of Dehydration Leading to Severe Symptomatic Hypercalcemia.

The American journal of case reports, 2022

Research

Current management strategies for hypercalcemia.

Treatments in endocrinology, 2003

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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