What is Polydipsia?
Polydipsia is not a disease or disorder but a symptom of many a condition characterized by an excessive need to take in fluid or the excessive thirst. The excess in need to quench a thirst therefore leads an affected individual to take in lots of water or any fluid which can potentially set forth an imbalance in the fluid and electrolyte of the body.
Polydipsia is often associated with polyuria which is defined as the excessive amount of urine released against the amount of fluid intake or relative to the amount of fluid intake.
Thirst is the physiologic need to take in an amount of water or any form of fluid. It is a corrective mechanism of the body to correct and control physiologically the fluid balance in the body. The excess in thirst can be a symptom of various medical conditions and recognizing the physiology of thirst will help in appreciating the significance of thirst as a symptom.
- Thirst will drive an individual to take in fluid as a regulatory component in which balance of fluid will keep the proper secretion of the antidiuretic hormone that is secreted by the hypothalamus when there is an increase in plasma osmolality.
- Drinking water or other fluid as a response to thirst thus helps in the maintenance of blood osmolality.
- The amount of thirst and the amount of fluid needed to quench the thirst is relative to the blood osmolality while the brain is being sent a signal to inhibit fluid overload.
- A decrease in the blood pressure or blood volume also stimulate or trigger thirsts.
- Vasopressin and human chorionic gonadotrophin are both thought to play a role in stimulating thirst during the process of pregnancy.
- Age advancement dulled thirst stimulus thus a decrease in primary thirst which on the other hand is recompensed by secondary drinking.
Psychogenic polydipsia is a condition characterized by the excessive urge to drink or take in fluid in an excessive amount even with the absence of stimulus. This form of polydipsia is associated with mental disorder such as Schizophrenia, depression and bipolar disorder. The etiology of the disorder among psychiatric patients has not been clearly understood but is thought to have resulted from neurochemical imbalances.
An extended or prolonged period of taking in excessive amounts of water or any fluid is potential to dilute or affect the concentration of sodium in the blood thereby resulting in low levels of sodium in the blood. Psychogenic polydipsia is also potentially life-threatening the extent of sodium dilution has reached the extent of causing seizure and cardiac arrest. The condition of the extreme amount of water intake may lead to hyponatremia and progress to water intoxication which can manifest with lethargy, confusion, psychosis, seizure and potentially death.
Patient with psychogenic polydipsia can be observed with utmost desire to seek water sources to quench their excessive thirst. Weight gain is also often apparent as a result of the inability of the kidney to compensate for the fluid overload. The manifestation of psychogenic polydipsia may be observed with undue thirst and the need of the patient to quench the thirst, nausea and vomiting, confusion and seizure. Polyuria or the condition of incessant need to urinate is also observable and is often associated with both the primary and psychogenic polydipsia.
Polydipsia can be influenced or caused by a lot of factors including numerous diseases and disorders that can trigger incessant thirst and need to quench that thirst.
Diabetes is the most implicated in the incidence of polydipsia. Both diabetes mellitus and diabetes insipidus can trigger polydipsia often as a side effect of diabetes medication. Polydipsia is also among the symptoms of diabetes and is also the effect of failure to take diabetes medication including the inadequacy in the dosage of the medication.
Deviation of pH level in normal plasma can also lead to polydipsia. The deviation in the levels is often the result of imbalance in the normal acid and base level of the body. This will lead an affected individual to a level of dehydration that will trigger excess need to quench the thirst.
Diarrhea is a condition characterized by increased looseness in the stools and increased bowel movement. This condition is potential for dehydration as a result of increased secretion of fluid into the intestine accompanied by a reduction in the absorption of fluid from the intestine thereby disrupting the fluid and electrolyte balance.
Severe burns can also lead to loss of fluid in the body which can cause an imbalance in the fluid and electrolyte of the body. The imbalance of fluid in the bloodstream can result to increase in the osmolality of the plasma thus the physiological driving force of thirst to maintain balance osmolality.
Pregnancy is also another factor considered to trigger excessive thirst and need to quench that thirst. The incessant thirst is triggered by the low level of osmolality which is thought to be affected by both the vasopressin and the human chorionic gonadotrophin.
Polydipsia is not a disease but often a symptom of an underlying medical condition. It is mostly associated with both diabetes mellitus and insipidus. Polydipsia is also often associated with polyuria that directly diagnosing the condition is rather difficult. Investigating or direct diagnosis of diabetes mellitus and diabetes insipidus can both be helpful in diagnosing polydipsia. Differential diagnosis proved helpful in diagnosing polydipsia to isolate it from different disorders related to the onset.
The blood serum test is also useful in diagnosing polydipsia through evaluation of osmolality of the extracellular fluids of the body. The revelation of decrease in the concentration of serum in the red blood cells, blood urea nitrogen and sodium signifies excessive water intake therefore polydipsia.
There are numerous treatments for polydipsia as the treatment is dependent on the cause or the underlying condition associated with the onset of polydipsia.
Desmopressin is the drug of choice for polydipsia associated with diabetes and nocturnal polydipsia. It is a synthetically produced drug that acts by replacing the vasopressin and aids in controlling both polydipsia and polyuria by reducing the production of urine.
Treatment of psychogenic polydipsia is different from non-psychogenic polydipsia. Psychogenic polydipsia involves dietary controls and monitoring of daily weight fluctuations including evaluation and management of damage to the urinary system based on the extent and damage to functions.
Early diagnosis and prompt treatment of polydipsia is essential in preventing further complications and irreversible damages which can be potentially life-threatening.