An Overview of Polyuria (Excessive Urination)

Symptoms, causes, diagnosis, and treatment

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Polyuria is when your body produces too much urine, more than 3 liters of urine a day for adults. It refers specifically to the amount of urine excreted daily, not the frequency of bathroom trips.

Polyuria is not a medical condition in itself, but it can be a symptom of other illnesses. Common causes include diabetes, kidney disease, and certain medications. It can also be caused by pregnancy, an electrolyte imbalance, excess caffeine, and drinking alcohol.

This article explains polyuria symptoms and causes. It also discusses how polyuria is diagnosed and treated.

Related Terms

Polyuria: Excessive output of urine

Nocturia: Waking up more than once a night to urinate

Polydipsia: Excessive thirst

Polyuria Symptoms

Polyuria literally translates to "urinating too much" and may be the only symptom one experiences. In general, an adult voids up to 2.5 liters of urine daily. If the amount excreted is more than 3 liters, it's considered abnormal.

Depending on the cause, there are other symptoms that can accompany polyuria. When the cause is either diabetes insipidus or diabetes mellitus, polyuria is usually coupled with excessive thirst (polydipsia).

Frequent urination, especially at night (nocturia), is often associated with polyuria, but it doesn't have to be.

Polyuria Causes

There are myriad causes of polyuria, ranging from drinking too much water to serious health complications like kidney failure. The following causes of polyuria are the most common.

Diabetes Mellitus

Diabetes mellitus is a condition caused by the body's inability to adequately control blood sugar, either because it is unable to properly manufacture insulin or a has resistance to the effects of insulin. Diabetes mellitus leads to higher osmolarity in the bloodstream because of increased sugar levels.

Think of the blood as a bit syrupy in a patient with diabetes mellitus. The kidneys must work to filter out the increased sugar by creating more urine.

Diabetes Insipidus

Diabetes insipidus is completely different from diabetes mellitus and doesn't have anything to do with blood glucose levels. Instead, diabetes insipidus is related to polyuria directly in its connection to arginine vasopressin (AVP), an antidiuretic hormone.

Central diabetes insipidus is caused by a lack of arginine vasopressin secretion due to a neurological condition. Nephrogenic diabetes insipidus is due to failure of the kidney to respond to AVP. Central diabetes insipidus can be acquired from a medical or traumatic brain injury. Nephrogenic diabetes insipidus is usually inherited.

Diuretic Medications

Certain medications are designed to increase urination to treat conditions like congestive heart failure and high blood pressure. Those medications can lead to polyuria if the dosages are not correct. Your physician will adjust the dosing of your medications as necessary to avoid unnecessary urination.


Lithium is a medication used to control mood disorders. It is almost entirely excreted from the body in urine and can have a profound effect on the kidneys in patients who take it regularly. Lithium can cause polyuria and polydipsia as a result of lithium-induced nephrogenic diabetes insipidus.

If lithium is discontinued early enough once the polyuria is noticed, the symptoms can be reversed without any long-term damage.

However, if polyuria is present and lithium is not discontinued, irreversible damage to the kidneys can cause permanent polyuria.

Alcohol or Caffeine Intake

Both alcohol and caffeine have known diuretic effects. Drinking either one to excess is capable of triggering polyuria to the point of developing dehydration. Alcohol is always a diuretic, even for people who drink alcohol on a regular basis. The diuretic effects of caffeine can decrease over time in people who regularly drink it.


Polyuria is a common symptom in early pregnancy. It is caused by an increase in progesterone and human chorionic gonadotropin (HCG). Polyuria in pregnancy typically resolves after the first trimester.

Polyuria in the second trimester can be a sign of gestational diabetes. Talk to your healthcare provider if you are concerned about excessive urination during pregnancy.

Polyuria Diagnosis

Polyuria is a symptom rather than a medical condition in its own right. There is no actual diagnosis of polyuria. However, the underlying cause of polyuria can be diagnosed once the symptom appears. The process of diagnosis for each cause is different. In every case, the physician will begin with determining the time of onset of polyuria and whether it came on suddenly or gradually over time.

Diabetes Mellitus vs. Diabetes Insipidus

If the onset of polyuria follows a significant neurological issue, such as traumatic brain injury or stroke, it could be a symptom of central diabetes insipidus.

Polyuria and polydipsia are both signs of diabetes mellitus as well as diabetes insipidus. Both conditions are significant and require further tests. The physician will want to measure the patient's hemoglobin A1C, a blood test that retroactively measures the average blood glucose levels over the previous six months.

The physician most likely will also order a urine glucose test to see if the body is excreting sugar in the urine, a sign of diabetes mellitus.

Polyuria Treatment

The most effective treatment for polyuria is aimed at the underlying cause. For example, lithium-induced nephrogenic diabetes insipidus could potentially be treated by discontinuing the lithium. Polyuria caused by diabetes mellitus is likely to improve once the patient's blood glucose levels are controlled.

Polyuria that cannot be corrected by treating the underlying cause is often treated with one of several medications that come from many different classes. One hallmark of polyuria is the diluted nature of the urine produced—it's composed of more water than urine.

Some treatments for polyuria include giving a type of diuretic, which usually increases urine output because it improves the way urine is processed in the kidneys.

A Word From Verywell

If you suspect that you are urinating too much (or too often), it's time to contact your primary physician, especially if you are also always thirsty. Polyuria can be treated and is not dangerous in the short term. However, it's crucial to get it corrected so that any potential underlying condition doesn't go untreated. Rest assured that early intervention with polyuria, as with any health condition, is key to managing and treating your health in the best way possible.

Frequently Asked Questions

  • What causes frequent urination?

    Frequent urination (polyuria) has several causes, including diabetes mellitus, diabetes inspidus, kidney disease, liver failure, diuretic medications, chronic diarrhea, Cushing's syndrome, polydipsia, alcohol, caffeine, hypercalcemia, and pregnancy.

  • Is polyuria painful?

    Polyuria is not usually described as being painful. The word dysuria is used to describe urination that is painful, and it can be a sign of an underlying health issue.

  • How frequent of urination is polyuria?

    Polyuria is not defined by the number of times you urinate, but rather the amount. Urine output in excess of 3 liters a day or more is considered polyuria.

  • Can you have polyuria without diabetes?

    Yes. While polyuria is a common sign of diabetes, it can be caused by other things. Pregnancy, certain medications, and too much caffeine can also cause excessive urination.

  • What medications cause polyuria?

    Medications that can cause increased urination include: 

    • Alpha-blockers
    • Antihistamines
    • Antipsychotics
    • Calcium channel blockers
    • Decongestants
    • Diuretics
    • Diabetes medications known as sodium-glucose cotransporter-2 (SGLT2) inhibitors
    • Mood stabilizers
    • Opioids
    • Tricyclic Antidepressants
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Bhasin B, Velez JC. Evaluation of Polyuria: The Roles of Solute Loading and Water Diuresis. Am J Kidney Dis. 2016;67(3):507-11. doi:10.1053/j.ajkd.2015.10.021

  2. Oelke M, De wachter S, Drake MJ, et al. A practical approach to the management of nocturia. Int J Clin Pract. 2017;71(11). doi:10.1111/ijcp.13027

  3. Christ-crain M. EJE Prize 2019 - New diagnostic approaches for patients with polyuria-polydipsia syndrome. Eur J Endocrinol. 2019; doi:10.1530/EJE-19-0163

  4. Merck Manual Professional Version. Polyuria

  5. National Kidney Foundation. Lithium and Chronic Kidney Disease

  6. U.S. National Library of Medicine. MedlinePlus. Urination - excessive amount

  7. Azab AN, Shnaider A, Osher Y, Wang D, Bersudsky Y, Belmaker RH. Lithium nephrotoxicity. Int J Bipolar Disord. 2015;3(1):28. doi:10.1186/s40345-015-0028-y

  8. Polyuria - frequent urination.

  9. Cleveland Clinic. Dysuria (painful urination).

Additional Reading
  • Afra K, James MT. Hyponatremia and polyuria in an older woman. CMAJ. 2013;185(12):1055–1058. doi:10.1503/cmaj.121757

  • Bedford JJ, Weggery S, Ellis G, et al. Lithium-induced nephrogenic diabetes insipidus: renal effects of amiloride. Clin J Am Soc Nephrol. 2008;3(5):1324–1331. doi:10.2215/CJN.01640408

  • Brown RJ, Epling BP, Staff I, Fortunato G, Grady JJ, McCullough LD. Polyuria and cerebral vasospasm after aneurysmal subarachnoid hemorrhage. BMC Neurol. 2015;15:201. doi:10.1186/s12883-015-0446-6

  • Kalra S, Zargar AH, Jain SM, et al. Diabetes insipidus: The other diabetes. Indian J Endocrinol Metab. 2016;20(1):9–21. doi:10.4103/2230-8210.172273

  • Oelke M, De Wachter S, Drake MJ, et al. A practical approach to the management of nocturia. Int J Clin Pract. 2017;71(11):e13027. doi:10.1111/ijcp.13027

By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.