- Hypocalcemia refers to an insufficient concentration of blood calcium. Mild hypocalcemia is usually asymptomatic while severe hypocalcemia leads to a characteristic clinical syndrome
- Because the concentration of blood calcium is primarily regulated by Parathyroid Hormone (PTH) and Vitamin D, derangements of these endocrine hormones are the most likely etiologies leading to hypocalcemia. Etiologies associated with hypoparathyroidism or pseudo-hypoparathyroidism can result in hypocalcemia.
- Because of common use of blood chemistries in clinics today, hypocalcemia is typically detected prior to any overt symptomology. However, when blood calcium concentrations drop sufficiently, a characteristic clinical syndrome arises as described below. The symptoms associated with the clinical syndrome of Hypercalcemia are primarily due to defects in conduction of electrical signals. Recall that entry of calcium into neurons and myocytes occurs during conduction of action potentials.
- Severe Hypercalcemia:
- Parasthesias: Tingling in fingers and toes
- Chvostek Sign: Hyperreflexia in muscles of the face, when tapped results in twitching
- Trousseau Sign: Spasm in muscles of hand and distal arm after inflation of manometer for a few minutes