Hypocalcaemia

CLINICAL DIAGNOSTIC MANUAL

Hypocalcaemia is defined as a plasma calcium concentration below 8.5 mg/dL. Calcium is an essential mineral for numerous biological functions, including muscle contraction, blood clotting, and nerve transmission.

Hypocalcaemia can result from disorders affecting intestinal absorption, renal losses, or hormonal imbalances regulating calcium metabolism.

This condition can present with neuromuscular, cardiovascular, and neurological symptoms that require prompt intervention to prevent severe complications.

Pathology	Clinical Symptoms and Signs	Suspected Diagnosis	Confirmatory Diagnosis
Vitamin D deficiency	Tetany, paraesthesia, carpopedal spasms, muscle weakness	History of limited sun exposure, poor vitamin D intake	Serum calcium and vitamin D measurement, PTH levels
Hypoparathyroidism	Tetany, paraesthesia, Chvostek’s sign, Trousseau’s sign, seizures	History of thyroid or parathyroid surgery, clinical symptoms	Serum calcium, PTH, phosphate levels, ECG
Chronic renal failure	Tetany, paraesthesia, carpopedal spasms, fatigue, hypertension	History of chronic kidney disease, uraemic symptoms	Serum calcium and phosphate measurement, renal function (creatinine, BUN), PTH levels
Pseudohypoparathyroidism	Tetany, paraesthesia, carpopedal spasms, neuromuscular signs	History of PTH resistance, phenotypic features	Serum calcium and phosphate measurement, PTH, genetic studies if necessary
Pancreatitis	Severe abdominal pain, nausea, vomiting, tetany, paraesthesia	History of acute pancreatitis, clinical symptoms	Elevated amylase and lipase, serum calcium levels, abdominal imaging (CT, MRI)
Fluid overload	Tetany, paraesthesia, carpopedal spasms, signs of volume overload (edema, dyspnoea)	History of large-volume intravenous fluid administration	Serum electrolytes, volume status evaluation
Rhabdomyolysis	Severe muscle pain, weakness, dark urine, tetany, paraesthesia	History of extensive muscle injury, clinical symptoms	Elevated CK, myoglobin in urine, serum calcium levels, renal function tests