NOTES

NOTES
HYPERPARATHYROIDISM &
HYPOPARATHYROIDISM

GENERALLY, WHAT ARE THEY?

PATHOLOGY & CAUSES SIGNS & SYMPTOMS
▪ An imbalance of parathyroid hormone ▪ See individual disorders
(PTH) due to overproduction or
underproduction by the parathyroid gland
resulting in impaired regulation of calcium DIAGNOSIS
and other electrolytes
LAB RESULTS
Hyperparathyroidism ▪ Measure serum PTH, calcium, phosphate,
▪ ↑ PTH → ↑ bone resorption and ↑ renal magnesium, 25-hydroxyvitamin D, urine
reabsorption of calcium → ↑ serum calcium calcium
levels → asymptomatic or symptomatic
hypercalcemia
OTHER DIAGNOSTICS
Hypoparathyroidism ▪ Genetic testing
▪ ↓ PTH → ↓ serum calcium → symptomatic
hypocalcemia
TREATMENT
RISK FACTORS
MEDICATIONS
▪ Hyperparathyroidism
▪ Hyperparathyroidism
▫ Genetic mutations, chronic kidney
▫ Vitamin D analogs, calcimimetics,
disease, ↓ vitamin D intake/absorption,
bisphosphonates
hyperplasia of parathyroid glands
▪ Hypoparathyroidism
▪ Hypoparathyroidism
▫ IV calcium gluconate (acute), vitamin
▫ Most commonly iatrogenic cause due
D analogs, synthetic PTH, thiazide
to accidental removal or damage to
diuretics (↓ renal calcium excretion)
parathyroid blood supply during thyroid
surgery
SURGERY
COMPLICATIONS ▪ Hyperparathyroidism
▪ Hyperparathyroidism ▫ Partial/complete parathyroidectomy;
radiofrequency ablation
▫ Osteoporosis, osteitis fibrosa
cystica, nephrolithiasis, keratopathy,
symptomatic hypercalcemia (e.g. OTHER INTERVENTIONS
hypertension, cardiac arrhythmias) ▪ Hyperparathyroidism
▪ Hypoparathyroidism ▫ Physical activity to ↓ bone resorption,
▫ Symptomatic hypercalcemia (e.g. maintain hydration to ↓ nephrolithiasis,
respiratory paralysis, cardiac vitamin D supplements
arrhythmias) ▪ Hypoparathyroidism
▫ Calcium, magnesium, and vitamin D
supplements

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 NOTES
HYPERPARATHYROIDISM
osms.it/hyperparathyroidism
COMPLICATIONS
PATHOLOGY & CAUSES
Primary
TYPES ▪ Brown tumors, large bone cysts (due to
high osteoclast activity)
Primary
▪ Parathyroid gland creates PTH
independently of calcium levels, does not SIGNS & SYMPTOMS
respond to normal feedback mechanisms
▪ “Stones, thrones, bones, groans, and
Secondary
psychiatric overtones”; see mnemonic
▪ Parathyroid gland hyperplasia, excess
parathyroid hormone secreted in response Primary, tertiary
to chronic hypocalcemia ▪ Slower muscle contractions caused
▪ Impaired kidney function; kidneys do not by less excitable neurons secondary to
filter phosphate properly into urine, make hypercalcemia
insufficient calcitriol
▫ AKA renal osteodystrophy (bone pain, Secondary
fracture) ▪ Bone resorption/renal osteodystrophy;
▪ Altered calcium, phosphate levels → calcification of blood vessels, soft tissues
increased parathyroid hormone levels →
bone resorption
MNEMONIC
Tertiary Signs and symptoms of
▪ Develops in individuals with secondary hyperparathyroidism
hyperparathyroidism for many years, often Stones: calcium-based kidney
due to hyperplasia of parathyroid glands stones, gallstones
▪ Autonomous secretion of PTH separately Thrones: toilet; polyuria
from blood calcium levels (frequent urination) from
▫ Even if causes of secondary impaired sodium, water
hyperparathyroidism (e.g. renal reabsorption
transplant) corrected, increased PTH Bones: pain from chronic
persists hormone-driven
demineralization
RISK FACTORS Groans: constipation, muscle
weakness
Primary Psychiatric overtones:
▪ Genetic mutations depressed mood, confusion
▫ Multiple endocrine neoplasia (MEN)
syndrome

OSMOSIS.ORG 103
 DIAGNOSIS
LAB RESULTS
Primary
▪ High total serum calcium (hypercalcemia),
low phosphate (hypophosphatemia), high
PTH valve during diastole
▪ Hypercalciuria from excess calcium loss
through urine, may cause dehydration
▪ Serum 25-hydroxyvitamin D
▫ Determine type
Figure 17.1 An ultrasound of the neck
Secondary demonstrating a large parathyroid adenoma
▪ Low calcium, high phosphate, low vitamin situated posteriorly and to the right of the
D right thyroid lobe. The skin surface is at the
top of the image.
Tertiary
▪ Normal-high calcium, high PTH, low
vitamin D

TREATMENT
MEDICATIONS
Primary, tertiary
▪ Calcimimetics Figure 17.2 A X-ray image of the
▫ Drugs that imitate calcium by attaching forearm demonstrating a brown tumor
to CaSR on parathyroid cells of the distal radius in an individual with
hyperparathyroidism.
▫ If surgery not an option

Secondary
▪ Hyperphosphatemia
▫ Phosphate binders
▪ Vitamin D supplements
▫ Increase calcium absorption, reduce
PTH synthesis
▪ Calcitriol, vitamin D analogs (doxercalciferol,
paricalcitol)
▫ Suppress PTH levels
▪ Calcimimetics
▫ Modulate CaSR → increase sensitivity of
serum calcium → decrease PTH levels

Tertiary

SURGERY
▪ Remove abnormal parathyroid glands

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 Chapter 17 Hyperparathyroidism & Hypoparathyroidism

HYPOPARATHYROIDISM
osms.it/hypoparathyroidism

PATHOLOGY & CAUSES SIGNS & SYMPTOMS

▪ Underproduction of parathyroid hormone ▪ Asymptomatic/life-threatening
(PTH); hypo- = under/low ▫ Degree, duration of hypocalcemia
▪ No parathyroid hormone → ↓ bone ▫ Muscular dysfunction → respiratory
resorption, ↓ renal calcium reabsorption, paralysis → death
↓ intestinal calcium reabsorption → ▪ ECG changes
hypocalcemia, hyperphosphatemia → ↑ cell
▫ Prolonged QT, ST
excitability → tetany, paresthesias, seizures,
arrhythmias ▫ Torsades des pointes
▫ Atrial fibrillation

CAUSES Acute
▪ Muscular spasms/cramps → tetany →
Autoimmune disorders
Chvostek, Trousseau signs
Magnesium deficiencies ▪ Perioral numbness, paresthesias, seizures

Latrogenic Chronic
▪ Most common ▪ Extrapyramidal movements → basal
▪ Thyroid/parathyroid surgery/radiation ganglia calcifications
▫ Dystonias, parkinsonism, athetosis,
Hereditary abnormalities hemiballismus, oculogyric crisis
▪ DiGeorge syndrome (DGS) ▪ Cataracts
▪ Autosomal dominant hypoparathyroidism ▪ Dermatologic manifestations
▪ Albright hereditary osteodystrophy ▫ Dry, coarse skin; brittle nails; patchy
(pseudohypoparathyroidism) alopecia
▫ Kidney resistance to PTH, increased
PTH

OSMOSIS.ORG 105
 Figure 17.3 Dry, brittle nails are a
dermatologic manifestation of chronic
hypoparathyroidism.

DIAGNOSIS
LAB RESULTS
▪ Hypocalcemia, low serum PTH
▪ Hypercalciuria

OTHER DIAGNOSTICS
▪ Medical history of thyroid surgery/radiation

TREATMENT
MEDICATIONS
▪ IV calcium gluconate (severe cases)
▪ Oral calcium (mild-moderate cases)
▪ Vitamin D supplementation
▪ Synthetic PTH

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