lowphosphorus

Low phosphorus, medically known as hypophosphatemia, is a condition in which the level of phosphate in the blood falls below the normal range. Phosphate is essential for energy production, bone mineralization, cell signaling, and acid-base balance. In adults, normal serum phosphate is roughly 2.5 to 4.5 mg/dL; levels below about 2.0 mg/dL are typically considered low, though reference ranges vary by laboratory.

Causes of hypophosphatemia include shifts of phosphate from extracellular fluid into cells, deficient intestinal absorption, and loss from the kidneys or through inadequate intake. Insulin release after meals, respiratory alkalosis, and refeeding after malnutrition can drive phosphate into cells. Malnutrition or chronic alcoholism, vitamin D deficiency, and certain medications such as aluminum-containing antacids or phosphate binders may reduce absorption. Renal phosphate wasting, Fanconi syndrome, hyperparathyroidism, and rarely genetic disorders can cause ongoing losses.

Symptoms depend on the severity and rate of decline and may include weakness, fatigue, bone pain, osteomalacia in adults or rickets in children, difficulty breathing, confusion, seizures, and, in severe cases, rhabdomyolysis or hemolytic anemia.

Diagnosis is by measurement of serum phosphate, often alongside calcium, magnesium, and kidney function tests. Treatment focuses on the underlying cause and may involve oral phosphate supplements for mild cases or intravenous phosphate for more severe hypophosphatemia, with careful monitoring to avoid complications such as hyperphosphatemia or hypocalcemia.