Psychogenic polydipsa is a mental disorder where the patient feels the need to drink water, or other liquids, obsessively.
The defining symptom of psychogenic polydipsa is often the hardest to notice. Excessive thirst is often expained away as being normal, and most people would not associate it with a serious medical condition. Individuals with this condition are constantly drinking water or other liquids, without a physical need for it. A large amount of urine (over five quarts) will be produced daily.
The diagnosis of this condition is usually done on the basis of other conditions the patient may have. It is only seen in patients with schizophrenia or diabetes insipidus. An individual with either of these conditions may be monitored for the amount of fluids they are drinking, as a precaution.
There are also tests that can help to confirm a diagnosis. Physicians will look for very diluted urine and elevated serum glucose levels. A physician may also withhold water to see if the patient becomes rapidly dehydrated. Because the patient has been ingesting, and then eliminating, large amounts of water, it is actually very easy for them to become dehydrated. The amount of urine they eliminate leaves them with little extra water in their bodies, as their bodies are now expecting the water to be quickly replenished.
In order to treat an individual with this condition, a doctor will first establish, based on weight, the amount of water that the patient actually needs. Psychiatric treatment will be used to help the patient reduce their psychological need for the excess of water. To prevent the patient from seeking out and drinking extreme amounts of water, doctors might try redirection (distraction), keeping them in their room at a hospital, and, in very extreme cases, possibly even physical restraint.
There are also some medications that can be used to treat this condition. Pindolol and Losartan have both been used as treatments, and there are other medications still in drug trials that may also prove useful. Most often, a diuretic will be prescribed, to help eliminate the excess of water and to aid the body in returning to a normal state of hydration.
The problem with psychogenic polydipsa is that, as the amount of water in the body increases, the amount of sodium decreases, to a very dangerous level. The excess water in the body can also affect brain cells, potentially leading to confusion, lethargy, seizures or, in extreme cases, a coma. If this condition comes on suddenly, as opposed to being a problem that develops over time, there is a greater risk to the brain and other organs, as they have not been able to slowly adapt to the changes in hydration.
Overhydration: The Merck Manual, http://www.merck.com/mmhe/ag/sec12/ch158/ch158c.html Accessed December 2009.
Psychogenic Polydipsa Review: Abstract http://www.springerlink.com/content/m275772822277u03/ Accessed December 2009.
Polydipsa, http://www.wrongdiagnosis.com/d/diabetes/book-diseases-10a.htm Accessed December 2009.