What are the signs and symptoms of hypercalcemia?

Signs and Symptoms of Hypercalcemia

The clinical presentation of hypercalcemia varies directly with severity and rapidity of onset, ranging from asymptomatic in mild cases to life-threatening manifestations including confusion, somnolence, coma, dehydration, and acute renal failure in severe cases. 1, 2

Severity-Based Clinical Presentation

Mild Hypercalcemia (10-11 mg/dL)

• Often completely asymptomatic, detected only on routine laboratory screening 1, 2
• When symptomatic (approximately 20% of cases), presents with subtle constitutional symptoms: 2
  • Fatigue
  • Constipation
  • Polyuria and polydipsia 1

Moderate Hypercalcemia (11-12 mg/dL)

• Gastrointestinal manifestations become prominent: 1, 3
  • Nausea and vomiting
  • Abdominal pain
• Neurological symptoms emerge: 1, 3
  • Confusion
  • Myalgia
• Renal symptoms persist: 1
  • Polyuria
  • Polydipsia

Severe Hypercalcemia (>14 mg/dL)

• Life-threatening emergency with multisystem involvement: 1, 2
• Neurological crisis: 1, 2
  • Altered mental status and confusion
  • Somnolence progressing to coma
• Cardiovascular compromise: 1
  • Bradycardia
  • Hypotension
• Renal failure: 1, 2
  • Acute kidney injury
  • Severe dehydration from ongoing polyuria
• Gastrointestinal distress: 2, 4
  • Severe nausea and vomiting contributing to dehydration

System-Specific Manifestations

Neuromuscular System

• Constitutional symptoms (fatigue, weakness) in mild cases 2
• Progressive confusion and altered mental status as severity increases 1, 5
• Somnolence and coma in severe cases 2, 4

Gastrointestinal System

• Constipation in mild hypercalcemia 2
• Nausea, vomiting, and abdominal pain in moderate to severe cases 1, 3, 5

Renal System

• Polyuria and polydipsia across all severity levels 1, 5
• Acute renal failure in severe hypercalcemia 1, 4
• Kidney stones (particularly in chronic primary hyperparathyroidism) 6

Cardiovascular System

• Bradycardia in severe cases 1
• Hypotension secondary to dehydration 1

Musculoskeletal System

• Myalgia in moderate hypercalcemia 1
• Bone pain (particularly in malignancy-associated hypercalcemia or chronic hyperparathyroidism) 6

Critical Clinical Context

The rapidity of onset significantly influences symptom severity—hypercalcemia developing over days to weeks causes more severe symptoms than the same calcium level developing gradually over months. 2, 4 This explains why malignancy-associated hypercalcemia (rapid onset) typically presents with more severe symptoms than primary hyperparathyroidism (gradual onset), even at similar calcium levels. 6, 4

Important caveat: The degree of symptoms does not always correlate perfectly with absolute calcium levels, as chronicity allows for physiologic adaptation. 4 A patient with chronic mild hypercalcemia from primary hyperparathyroidism may be completely asymptomatic, while another with rapidly rising calcium from malignancy at the same level may be severely symptomatic. 6

Physical Examination Findings to Assess

• Volume status assessment (dehydration is nearly universal in symptomatic cases) 1, 7
• Neurological examination (mental status, level of consciousness) 1
• Cardiovascular examination (heart rate, blood pressure) 1
• Abdominal examination (tenderness, distension) 1
• Musculoskeletal examination (bone tenderness, muscle weakness) 1
• Lymphadenopathy (suggests malignancy or granulomatous disease) 1