What are the symptoms of hypocalcemia?

Symptoms of Hypocalcemia

Hypocalcemia presents with a spectrum of neuromuscular, cardiovascular, and neuropsychiatric manifestations ranging from mild paresthesias to life-threatening seizures and cardiac arrhythmias, with neuromuscular irritability and tetany being the hallmark features. 1

Neuromuscular Symptoms

The most characteristic manifestations involve increased neuromuscular excitability:

• Paresthesias (tingling/numbness) affecting the hands, feet, and perioral region are among the most common early symptoms 1
• Muscle cramps and spasms occur frequently and may progress to frank tetany 1
• Tetany represents severe neuromuscular irritability with painful muscle contractions 2, 3

Neurological Manifestations

Hypocalcemia significantly affects the central nervous system:

• Seizures may be the presenting symptom, particularly in patients with underlying seizure disorders 1
• Confusion or altered mental status can develop in severe cases 1
• Irritability and emotional changes are common neurological symptoms 1
• Behavioral changes including anxiety or depression may occur and can be mistaken for primary psychiatric conditions 1, 4

Movement Disorders

Calcium deficiency affects basal ganglia function:

• Extrapyramidal symptoms including dystonia, myoclonus, tremors, motor tics, and parkinsonism-like symptoms can occur 5
• These movement disorders result from calcium's role in neurotransmission within the basal ganglia 5

Cardiovascular Symptoms

Cardiac manifestations can be life-threatening:

• QT interval prolongation on electrocardiogram is a common finding 1
• Cardiac arrhythmias including ventricular tachycardia and fibrillation may occur 1
• Cardiomyopathy is a rare but serious complication 1

General Symptoms

• Fatigue is a frequent nonspecific complaint 1

Special Populations and Clinical Context

Neonates and Infants

Infants born to mothers with hypocalcemia should be monitored for neuromuscular irritability, apnea, cyanosis, and cardiac rhythm disorders 6

Pregnancy

Maternal hypocalcemia can result in spontaneous abortion, premature and dysfunctional labor, and possibly preeclampsia 6

Important Clinical Pitfalls

• Symptoms may be subtle and easily confused with psychiatric conditions such as depression or anxiety, leading to delayed diagnosis 1, 4
• Severity correlates with acuity: Acute hypocalcemia typically presents with more dramatic neuromuscular symptoms (tetany, seizures), while chronic hypocalcemia may have more subtle manifestations 2, 3
• Risk increases during biological stress including surgery, childbirth, infection, fractures, perioperative periods, puberty, and pregnancy 1, 4
• Lifestyle factors such as alcohol consumption and carbonated beverage intake (especially colas) may worsen symptoms 1, 4

Diagnostic Approach

When hypocalcemia is suspected based on symptoms:

• Measure pH-corrected ionized calcium as the most accurate diagnostic test 1, 4, 5
• Check parathyroid hormone (PTH) levels to determine if hypoparathyroidism is present 1
• Assess magnesium levels as hypomagnesemia can contribute to hypocalcemia and must be corrected first 1, 4
• Monitor thyroid function as hypothyroidism may be associated 1
• Evaluate renal function (creatinine) for potential kidney involvement 1