What is Primary Polydipsia?
Primary polydipsia (PP) is a condition that involves drinking too much fluid. This leads to excessive urination, with diluted urine and can ultimately result in a low sodium level in the blood, a condition called hyponatremia. When we say someone has polyuria, it means they are producing more than 40-50 ml/kg of urine in a day.
Primary polydipsia comes in two varieties; psychogenic polydipsia and dipsogenic polydipsia. Psychogenic polydipsia often appears in people with mental health disorders. Dipsogenic polydipsia, also known as compulsory water drinking, is either a result of conscious efforts to drink lots of water, perhaps in the belief it is healthy, or due to problems in a part of the brain called the hypothalamus. The concept of compulsory water drinking, where people drink more water in the belief it promotes good health, has been becoming more common due to popular lifestyle programs.
In this brief explanation, we will talk about the cause, how the disorder develops, how it’s diagnosed, and potential treatment options for both psychogenic polydipsia and dipsogenic polydipsia. An interesting side note is the condition known as beer potomania, which often surfaces in people with chronic alcoholism who drink lots of beer and may not have a balanced diet. While not exactly fitting the definition of polyuria, it can also cause hyponatremia. Psychogenic polydipsia is common in people with various psychiatric conditions, particularly those with schizophrenia. The exact reasons aren’t fully understood yet, but several theories exist. A serious issue that can result from primary polydipsia is hyponatremia.
One disorder often confused with primary polydipsia is diabetes insipidus (DI). To help differentiate between them, doctors have traditionally used the water deprivation test, which indirectly measures a hormone called arginine vasopressin (AVP), along with giving a medication called desmopressin. This strategy also assists in separating central from nephrogenic diabetes insipidus. However, this method has its flaws. New techniques are being examined, such as measures of another hormone called copeptin, both before and after the administration of high-salt solutions or arginine.
When it comes to treating this condition, there’s no one-size-fits-all answer. Generally, doctors recommend controlling water intake, but this is hard for people with psychogenic polydipsia who may have compulsive behavior. Adjusting certain medications that have side effects impacting the body’s ability to retain water could provide some benefits. Different types of drugs have been tested, but so far nothing has proven successful. Different types of behavioral treatments have shown varying levels of effectiveness. But working together as a health care team can definitely improve outcomes.
What Causes Primary Polydipsia?
Primary polydipsia, a condition where a person drinks excessive amounts of water, often accompanies developmental disorders like autism and intellectual disability. It is also common among individuals affected by psychiatric disorders like schizophrenia, bipolar disorder, and severe depression. The term ‘psychogenic polydipsia’ was coined after recognizing the condition in patients with schizophrenia. Notably, patients with severe mental disorders may experience episodes of hyponatremia-polydipsia syndrome, where excessive thirst and low sodium levels occur during their psychotic episodes.
People with non-psychotic, axis-1 psychiatric disorders can also experience polydipsia, often resembling a compulsive need to drink water. These individuals rarely develop hyponatremia, or low sodium in the blood, unless they also have other contributing factors like taking certain kinds of water pills, known as thiazide diuretics.
Another kind of excessive thirst, known as dipsogenic polydipsia, can occur in individuals who have inflammation, infection, or infiltration in a region of the brain called the hypothalamus. A subset of this condition, known as habitual polydipsia, is seen in people who believe that drinking large amounts of water can improve their overall health. This belief and the resulting excessive drinking of water have been increasingly common in recent years.
Risk Factors and Frequency for Primary Polydipsia
Psychogenic polydipsia, or the excessive drinking of water often due to psychological reasons, is commonly seen in people with various mental health conditions such as depression, bipolar disorder, and particularly schizophrenia. In fact, 18% of patients in psychiatric institutions exhibit signs of polydipsia. On another note, dipsogenic polydipsia, a form that’s closely related to a type of diabetes known as diabetes insipidus, is showing an increased prevalence due to the rise of healthy lifestyle programs—but it’s more common in women.
The exact number of people with dipsogenic polydipsia is not certain. Beer potomania, another condition related to excessive drinking, is notably more common in men. Regular, excessive water consumption can also be seen in those who are very active and health-conscious.
Signs and Symptoms of Primary Polydipsia
People may have a history of mental health issues or diseases that affect the brain. It’s also common for those who drink a lot of fluids and are conscious about their health to show symptoms of low sodium levels in the blood, or hyponatremia. These symptoms may include feeling sick, throwing up, confusion, problems with coordination, a coma, seizures, and even death. When investigating these symptoms, it’s important for the doctor to understand the person’s past health history, including any brain surgery or injuries. They will also want to know about autoimmune or infectious diseases the person may have had. Information about medication, smoking, and alcohol use is also important.
- History of psychiatric conditions or diseases affecting the brain
- Tends to drink a lot of fluids and is health conscious
- Symptoms of hyponatremia: nausea, vomiting, confusion, problems with coordination, coma, seizures, and even death
- Medical history, including events such as brain surgery or trauma
- Inquiry into autoimmune and infectious diseases
- History of medication use
- Personal history of smoking and alcohol use
Testing for Primary Polydipsia
To help understand your symptoms and diagnosis, your doctor will ask you about your health history. They may order blood and urine tests to check your body’s electrolyte levels and how well your kidneys are performing. Testing the concentration (or ‘osmolality’) of your blood and urine over 24 hours is another way to assess kidney function.
Your doctor may also use imaging studies such as a CT scan or an MRI of the brain. These tests create detailed pictures of your brain to ensure that there are no underlying health issues contributing to your symptoms.
Finally, to get a complete picture of your health, your doctor may ask you about your lifestyle. This could include questions about your alcohol consumption and how much liquid you drink daily. All this information helps your doctor determine the best plan for your care.
Treatment Options for Primary Polydipsia
In severe cases of hyponatremia, which is an abnormally low level of sodium in the blood, a patient may need treatment in an ICU, or intensive care unit, where they’ll be frequently monitored and given a strong saline solution via an IV. Patients who are not critically ill, and hence do not need an ICU, may have their water intake restricted once it is established that they are passing a lot of diluted urine. However, care must be taken for patients who also have diabetes insipidus, as restricting their water intake can lead to dehydration. Checking the concentration of substances in the urine before and after limiting water intake is important for assessment.
Treating primary polydipsia, a condition that causes excessive thirst and compulsive water drinking, can be challenging as there is no standard proven treatment. One approach is to limit water intake, but it can be hard for patients to adhere to such a regimen due to their strong urge to drink water. Educating individuals about the condition and encouraging them to consciously reduce their water intake can help manage the symptoms. A comprehensive review conducted in 2006 analyzed two clinical trials focusing on pharmacological treatments for patients with primary polydipsia who also had psychiatric illnesses. However, the review found that the results were not significant enough to change current clinical practices.
The review included studies that examined the effects of different types of drugs like antidepressants, antipsychotics, beta-blockers, ACE inhibitors, mood stabilizers, drugs that block receptors for angiotensin, a hormone that raises blood pressure, tetracyclines, which are a type of antibiotic, opiate antagonists, alpha-adrenergic receptor blockers, and placebo. Attempts at using behavioral treatments have shown mixed results.
At this time, there is no proven pharmaceutical or behavioral treatment for primary polydipsia. The evidence that supports either method is weak. Treatment should be determined on a case-by-case basis, taking into consideration the patient’s unique situation. The medical provider should use their discretion in deciding the most suitable course of action.
What else can Primary Polydipsia be?
If you’re frequently feeling thirsty and urinating more than usual, you might be experiencing a condition called primary polydipsia (PP). However, it’s important to first eliminate more common conditions that can also cause these symptoms like high blood sugar (hyperglycemia) or high calcium levels (hypercalcemia) in the blood. Other conditions that could show similar symptoms include diabetes insipidus, which could either be central or nephrogenic, and beer potomania. In beer potomania, however, the total amount of urine produced is not as high as it is in polyuria (a condition that consists of excessive urination).
If confirmed that you’re producing excessive urine (>40-50 ml/kg/24hrs) and the concentration of dissolved substances in your urine is low (<800 mOsm/kg), there are some tests that can help to diagnose what’s causing these symptoms. For example, a blood test to measure your serum sodium level can provide clues. If your serum sodium level is less than 135 meq, it could be PP. If it is higher than 147, it might be diabetes insipidus.
If the serum sodium falls between 135 and 147, a water deprivation test would be performed. If urine production decreases and urine concentration increases when you’ve been deprived of water, you could have PP. In cases of diabetes insipidus, urination doesn’t decrease with water deprivation. A medication known as desmopressin can help differentiate if the diabetes insipidus is central or nephrogenic. If the urine concentration increases by more than 50% after the application of desmopressin, it signifies central diabetes insipidus, while an increase of less than 50% signifies nephrogenic diabetes insipidus.
However, there have been some concerns regarding the sensitivity and accuracy of the water deprivation test as it requires a lengthy period of deprivation to accurately diagnose and differentiate between these conditions.
Another method that is being explored is the direct measurement of a hormone called arginine vasopressin (AVP) or copeptin, which is a surrogate marker for vasopressin. A copeptin value higher than 21.4 pmol/l at the start of the test establishes a diagnosis of nephrogenic diabetes insipidus. If the value is less than 21.4 pmol/l, another test is performed that involves raising the serum sodium level to more than 150 mmol/l. This can be achieved through water deprivation or infusion of a salt solution under hospital supervision. If the level of copeptin is 4.9 pmol/l or greater after stimulation, primary polydipsia can be diagnosed. If it’s less than 4.9 pmol/l, it could be central diabetes insipidus.
Last but not least, pregnant women could present with low sodium levels in their blood without any polyuria or polydipsia symptoms. This is due to natural hormonal changes during pregnancy and is considered normal.
What to expect with Primary Polydipsia
The outlook for a patient mostly relies on the treatment used and the psychiatric disorder they have. The best way to prevent water intoxication, a condition when there’s too much water in the body, is by controlling how much water one drinks. However, sticking to this regime might sometimes be a problem for the patients.
Possible Complications When Diagnosed with Primary Polydipsia
Complications from a condition called primary polydipsia primarily come from a condition called hyponatremia (low sodium level in the blood). Symptoms of this condition can include feeling sick, throwing up, blurred vision, shaking, feeling dizzy, loss of coordination, confusion, feeling very tired, and, most often, seizures. It’s very important to carefully manage the sodium levels in someone with hyponatremia to avoid a serious condition called central pontine myelinolysis. This means not increasing the sodium level by more than 8-10 mmol/l in a day. If the level is corrected too quickly, water and a form of sugar called dextrose can be given. Central pontine myelinolysis is a serious risk because it can cause lasting severe neurological damage. And in the worst cases, hyponatremia could even result in death.
Common Symptoms:
- Feeling sick
- Throwing up
- Blurred vision
- Shaking
- Feeling dizzy
- Loss of coordination
- Confusion
- Feeling very tired
- Seizures
- Severe neurological damage due to central pontine myelinolysis
- Possibility of death
Preventing Primary Polydipsia
Patients should be educated about hyponatremia (a condition in which the level of sodium in the blood is too low) and the serious effects that it can cause. Keeping track of the amount of water consumed can be beneficial. Patients are also encouraged to keep their healthcare providers informed about any medications they are taking for mental health conditions. This information can help the healthcare provider adjust the medications as necessary, based on the patient’s progress.
Patients can be motivated to limit their water intake by using a reward system. The family of the patient also plays a significant role in supporting and reinforcing these behaviors. These actions can prevent or manage hyponatremia, helping patients to stay healthy.
