In station 5 you may be asked to assess a patient with pins and needles or numbness in their fingers/toes.


HISTORY (3 minutes) – she tells you the numbness is around her mouth, fingers, toes


Ask questions about symptoms of low calcium:

  • Muscle spasms/muscle twitching
  • Muscle cramps
  • Breathlessness (laryngospasm, bronchospasm)
  • Bone pain, abdominal pain, headache
  • Mood/irritable/anxious/fatigue
  • Confusion
  • Seizures
  • Cataracts, dental problems, kidney stones, gut problems

Ask questions about aetiology of low calcium:

  • Head and neck surgery or radiation
  • Problem with kidneys
  • Sunlight/vitamin D
  • Abdominal pain (Pancreatitis)
  • Autoimmune conditions- vitiligo, thyroid, addisons
  • Blood transfusion
  • Infiltrative: Wilsons- liver problems/tremor, Haemochromatosis- diabetes/tired/joint pains, Cancer


Fx of low calcium/hypoparathyroid disorders

Dx eg. bisphosphonates, chemotherapy



EXAMINE (3 minutes)


  • Observe for a short patient with round face, short neck, shortened 4th+5th metacarpals (pseudohypoparathyroidism “knuckle, knuckle, dimple, dimple” sign on closed fist)
  • Mouth- dental abnormalities
  • Neck examination
  • Abdominal examination
  • Offer to test for chvostek’s and trousseau’s signs
  • Neuro examination (brisk reflexes, extrapyramidal findings, fundoscopy for papilloedema)


ICE+ Explanation (2 minutes)


“I’d like to test your calcium level and if low replace it. I’ll check the level of other electrolytes too like magnesium.  I’d also like to get a tracing of your heart and an opinion from an endocrinology doctor.”






Confirm low calcium (and correct for abnormality in serum albumin)

Check Mg, K+, Phosphate, pH, PTH, vitamin D, U+E, ALP, amylase.

If autoimmune process is suspected: TFTs, ACTH and adrenal antibodies

24 hour urinary calcium

ECG- QT prolongation, heart block, VF

Renal USS (renal stones)

Brain MRI- basal ganglia calcification

Genetic testing

XR hands- shortened metacarpals





Kidney and bone resistance to PTH- low calcium, raised phosphate, raised PTH, low calcitriol, normal U+E. No urinary cAMP response to PTH.


Type 1a: Autosomal dominant. GNAS1 mutation. Albright hereditary osteodystrophy (AHO): round facies, short stature, short fourth and fifth metacarpal bones, obesity, subcutaneous calcifications and developmental delay.  NB: paternally transmitted mutations have the phenotype of AHO but with normal calcium, phosphate and PTH (pseudopseudohypoparathyroidism)


Type 1b- no phenotypic features of AHO. Similar biochemistry to AHO.


Type 2- no phenotypic features of AHO. NB: Normal or raised cAMP response in urine


Management: Treatment of hypocalcaemia and refer to endocrinology

Patients with pseudohypoparathyoridism may also require screening for other endocrinopathies, particularly hypothyroidism and hypogonadism




Causes of hypocalcaemia:


  1. Hypoparathyroidism (Low Ca, low PTH, Low Mg, raised P, normal ALP)
    1. Post-thyroidectomy/parathyroidectmy/radiation to neck/RI for thyroid/radical neck dissection
    2. Abnormal magnesium
    3. Infiltration eg. Haemochromatosis, thalassaemia, wilsons, mets, granulomatous
    4. Autoimmune
    5. Genetic eg. abnormal parathyroid development, Digeorge
    6. Idiopathic
  2. PTH resistance (Pseudohypoparathyroidism)
  3. Renal Disease
  4. Vitamin D deficiency
  5. Bisphosphonates, calcitonin, phenytoin
  6. Acute pancreatitis
  7. Blood transfusion
  8. Artefact (raised K+, low Mg, Low ALP)
  9. Rhabdomyolysis
  10. Tumour lysis
  11. Hyperphosphatemia


Written by Dr Sarah Kennedy


Resources used to write this document include those listed in the references section of this webpage and also: