Hyperphosphatemia

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Hyperphosphatemia
Classification and external resources
Phosphate Group.PNG
Phosphate group chemical structure
ICD-9 275.3
DiseasesDB 20722
eMedicine med/1097
MeSH D054559

Hyperphosphatemia is an electrolyte disturbance in which there is an abnormally elevated level of phosphate in the blood.[1] Often, calcium levels are lowered (hypocalcemia) due to precipitation of phosphate with the calcium in tissues. Average phosphorus levels should be between 0.81 mmol/L and 1.45 mmol/L.

Signs and symptoms[edit]

Signs and symptoms include ectopic calcification, secondary hyperparathyroidism, and renal osteodystrophy.

Causes[edit]

Causes of hyperphosphatemia[2]
Impaired renal phosphate excretion
  • Renal insufficiency
  • Hypoparathyroidism
    • Developmental
    • Autoimmune
    • After neck surgery or radiation
    • Activating mutations of the calcium-sensing receptor
  • Parathyroid suppression
    • Parathyroid-independent hypercalcemia
      • Vitamin D or vitamin A intoxication
      • Sarcoidosis, other granulomatous diseases
      • Immobilization, osteolytic metastases
      • Milk-alkali syndrome
    • Severe hypermagnesemia or hypomagnesemia
  • Pseudohypoparathyroidism
  • Acromegaly
  • Tumoral calcinosis
  • Heparin therapy
Massive extracellular fluid phosphate loads
  • Rapid administration of exogenous phosphate (intravenous, oral, rectal)
  • Extensive cellular injury or necrosis
    • Crush injuries
    • Rhabdomyolysis
    • Hyperthermia
    • Fulminant hepatitis
    • Cytotoxic therapy
    • Severe hemolytic anemia
  • Transcellular phosphate shifts
    • Metabolic acidosis
    • Respiratory acidosis

Hypoparathyroidism: In this situation, there are low levels of Parathyroid hormone (PTH). PTH normally inhibits renal reabsorption of phosphate, and so without enough PTH there is more reabsorption of the phosphate.

Chronic renal failure: When the kidneys aren't working well, there will be increased phosphate retention.

Drugs: hyperphosphatemia can also be caused by taking oral sodium phosphate solutions prescribed for bowel preparation for colonoscopy in children.

Treatment[edit]

High phosphate levels can be avoided with phosphate binders and dietary restriction of phosphate.

See also[edit]

References[edit]

  1. ^ "hyperphosphatemia" at Dorland's Medical Dictionary
  2. ^ Longo et al., Harrison's Principles of Internal Medicine, 18th ed., p.3089