What are the symptoms of hypercalcemia?

Symptoms of Hypercalcemia

The primary symptoms of hypercalcemia include extreme irritability, nausea, vomiting, constipation, muscle cramps, dehydration, confusion, lethargy, and in severe cases, somnolence and coma. 1, 2, 3

Classification of Hypercalcemia by Severity

• Mild hypercalcemia (total calcium <12 mg/dL or <3 mmol/L)

  • Often asymptomatic
  • May cause fatigue and constipation in approximately 20% of patients 3

• Moderate hypercalcemia (total calcium 12.0-13.5 mg/dL)

  • Constitutional symptoms become more common
  • Increased risk of dehydration 1

• Severe hypercalcemia (total calcium ≥14 mg/dL or ≥3.5 mmol/L)

  • Life-threatening emergency
  • Requires immediate intervention 1, 4

Symptom Manifestations by Body System

Neurological Symptoms

• Confusion
• Lethargy
• Impaired cognitive function
• Somnolence
• Coma (in severe cases)
• Lack of concentration 2, 3, 4

Gastrointestinal Symptoms

• Nausea
• Vomiting
• Constipation
• Abdominal pain
• Reduced appetite 2, 3, 4

Renal Manifestations

• Dehydration
• Hypercalciuria
• Nephrocalcinosis
• Polyuria
• Renal insufficiency 2, 4

Musculoskeletal Symptoms

• Muscle cramps
• Muscle pain
• Bone pain
• Weakness 2, 3

Cardiovascular Manifestations

• Hypertension
• Shortened QT interval on ECG
• Arrhythmias (in severe cases)
• Vascular calcification (with chronic hypercalcemia) 1

Special Considerations

Hypercalcemia in Infants

• Extreme irritability (a hallmark symptom)
• Vomiting
• Constipation
• Muscle cramps
• Failure to thrive 2

Hypercalcemic Crisis

Hypercalcemic crisis is defined as severe hypercalcemia (total calcium >3.5 mmol/L) with accompanying severe symptoms including:

• Severe dehydration
• Acute kidney injury
• Altered mental status
• Coma
• Cardiac arrhythmias 4, 5

Clinical Pearls and Pitfalls

Important Clinical Pearls

• Symptoms correlate with both the absolute calcium level and the rate of rise
• Rapidly developing hypercalcemia typically causes more severe symptoms than gradually increasing levels 3, 4
• Hypercalcemia can manifest as a psychiatric emergency with confusion, psychosis, or delirium 1
• Hypercalcemia-induced delirium is often reversible (in approximately 40% of episodes) 1

Common Pitfalls

• Failing to recognize hypercalcemia as the cause of nonspecific symptoms like fatigue, constipation, or mild confusion
• Not correcting calcium levels for albumin in hypoalbuminemic patients
• Overlooking hypercalcemia in patients with malignancy who develop new neurological symptoms
• Attributing symptoms to other conditions, especially in elderly patients 1, 3

Conclusion

Recognizing the symptoms of hypercalcemia is crucial for prompt diagnosis and treatment. The clinical presentation varies widely based on the severity, acuity of onset, and underlying cause. While mild hypercalcemia may be asymptomatic, severe hypercalcemia represents a medical emergency requiring immediate intervention to prevent significant morbidity and mortality.