Hyperphosphatemia
Encyclopedia
Hyperphosphatemia is an electrolyte disturbance
in which there is an abnormally elevated level of phosphate
in the blood
. Often, calcium
levels are lowered (hypocalcemia) due to precipitation of phosphate with the calcium in tissues.
, secondary hyperparathyroidism
, and renal osteodystrophy
.
: 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.
Osteomalacia
, which may be caused by the insufficient content of vitamin D
in the diet, the lack of sunlight, malabsorption
or renal disorders.
Drugs: hyperphosphatemia can also be caused by taking oral sodium phosphate solutions prescribed for bowel preparation for colonoscopy in children.
and dietary restriction of phosphate.
Electrolyte disturbance
Electrolytes play a vital role in maintaining homeostasis within the body. They help to regulate myocardial and neurological function, fluid balance, oxygen delivery, acid-base balance and much more. Electrolyte imbalances can develop by the following mechanisms: excessive ingestion; diminished...
in which there is an abnormally elevated level of phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
in the blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
. Often, calcium
Calcium in biology
Calcium plays a pivotal role in the physiology and biochemistry of organisms and the cell. It plays an important role in signal transduction pathways, where it acts as a second messenger, in neurotransmitter release from neurons, contraction of all muscle cell types, and fertilization...
levels are lowered (hypocalcemia) due to precipitation of phosphate with the calcium in tissues.
Signs and symptoms
Signs and symptoms include ectopic calcificationEctopic calcification
Ectopic calcification is a pathologic deposition of calcium salts in tissues. This can be a symptom of hyperphosphatemia.-References:*...
, secondary hyperparathyroidism
Hyperparathyroidism
Hyperparathyroidism is overactivity of the parathyroid glands resulting in excess production of parathyroid hormone . The parathyroid hormone regulates calcium and phosphate levels and helps to maintain these levels...
, and renal osteodystrophy
Renal osteodystrophy
Renal osteodystrophy or chronic kidney disease-mineral and bone disorder is a bone pathology, characterized by bone mineralization deficiency, that is a direct result of the electrolyte and endocrine derangements that accompany chronic kidney disease...
.
Causes
HypoparathyroidismHypoparathyroidism
Hypoparathyroidism is decreased function of the parathyroid glands with under production of parathyroid hormone. This can lead to low levels of calcium in the blood, often causing cramping and twitching of muscles or tetany , and several other symptoms...
: In this situation, there are low levels of Parathyroid hormone
Parathyroid hormone
Parathyroid hormone , parathormone or parathyrin, is secreted by the chief cells of the parathyroid glands as a polypeptide containing 84 amino acids...
(PTH). PTH normally inhibits renal reabsorption of phosphate, and so without enough PTH there is more reabsorption of the phosphate.
Chronic renal failure
Chronic renal failure
Chronic kidney disease , also known as chronic renal disease, is a progressive loss in renal function over a period of months or years. The symptoms of worsening kidney function are unspecific, and might include feeling generally unwell and experiencing a reduced appetite...
: When the kidneys aren't working well, there will be increased phosphate retention.
Osteomalacia
Osteomalacia
Osteomalacia is the softening of the bones caused by defective bone mineralization secondary to inadequate amounts of available phosphorus and calcium, or because of overactive resorption of calcium from the bone as a result of hyperparathyroidism...
, which may be caused by the insufficient content of vitamin D
Vitamin D
Vitamin D is a group of fat-soluble secosteroids. In humans, vitamin D is unique both because it functions as a prohormone and because the body can synthesize it when sun exposure is adequate ....
in the diet, the lack of sunlight, malabsorption
Malabsorption
Malabsorption is a state arising from abnormality in absorption of food nutrients across the gastrointestinal tract.Impairment can be of single or multiple nutrients depending on the abnormality...
or renal disorders.
Drugs: hyperphosphatemia can also be caused by taking oral sodium phosphate solutions prescribed for bowel preparation for colonoscopy in children.
Treatment
High phosphate levels can be avoided with phosphate bindersPhosphate binders
Phosphate binders are a group of medications used to reduce the absorption of phosphate and taken with meals and snacks. They are typically used in patients with chronic renal failure as they cannot get rid of the phosphates that get into their blood Phosphate binders are a group of medications...
and dietary restriction of phosphate.