Hyperphosphatemia Clinical Presentation

Updated: Aug 19, 2022
  • Author: Eleanor Lederer, MD, FASN; Chief Editor: Vecihi Batuman, MD, FASN  more...
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Typically, most patients with hyperphosphatemia are asymptomatic. Signs and symptoms of acute hyperphosphatemia result from the effects of hypocalcemia, with patients occasionally reporting symptoms such as muscle cramps, tetany, and perioral numbness or tingling. Other symptoms include bone and joint pain, pruritus, and rash.

More commonly, patients report symptoms related to the underlying cause of the hyperphosphatemia, generally uremic symptoms such as fatigue, shortness of breath, anorexia, nausea, vomiting, and sleep disturbances.

Therefore, information related to the causes of hyperphosphatemia, such as a history of diabetes mellitus or hypertension (causes of renal failure), a history of neck surgery or irradiation (causes of hypoparathyroidism), or a history of excessive vitamin D or milk ingestion, is important to obtain.

A search for the following historical clues may help to identify patients who are at risk for increased phosphorus levels:

  • Kidney disease: Past or present hemodialysis; adherence to renal (low phosphorus) diet; use of oral phosphate binders
  • Cancer: Leukemia, lymphoma, bone tumors, other cancers, chemotherapy treatment
  • Endocrinopathies (hypoparathyroidism and pseudohypoparathyroidism)
  • Trauma
  • Burns or heat-related illnesses
  • Prolonged immobilization
  • Metabolic or hematologic disorders, including genetic predisposition
  • Ischemic bowel (possible phosphorus elevations)

The patient’s medication history with regard to the following should also be obtained:

  • Oral phosphate binders
  • Potassium phosphate
  • Antacids
  • Bisphosphonates
  • Laxatives (oral/rectal) and enemas [41]
  • Nutritional supplements or hyperalimentation

Physical Examination

No aspects of the physical examination are specific to or pathognomonic of hyperphosphatemia. If the hyperphosphatemia is acute, especially if it is due to parenteral phosphate administration, the patient may be hypotensive or exhibit signs of hypocalcemia, such as a positive Trousseau or Chvostek sign, hyperreflexia, carpopedal spasm, or seizure.

Cataracts can be an ocular sign of hyperphosphatemia, but the cardiovascular (hypotension and heart failure, prolongation of the QT interval) and nervous systems are the most commonly affected by the condition.

Central nervous system (CNS) and neuromuscular signs and symptoms in patients with hyperphosphatemia include the following:

  • Altered mental status
  • Delirium
  • Obtundation
  • Coma
  • Convulsions and seizures
  • Muscle cramping or tetany
  • Neuromuscular hyperexcitability (ie, Chvostek and Trousseau signs)
  • Paresthesias (particularly perioral and distal extremities)