Polyuria Causes, Diagnosis, and Treatment

Polyuria occurs when your body produces too much urine, which is typically considered 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 usually a symptom of other illnesses. Common causes include diabetes, kidney disease, and certain medications. Pregnancy, an electrolyte imbalance, excess caffeine, and drinking alcohol can also contribute to polyuria.

Symptoms

Polyuria means “urinating too much,” and the main symptom is excessive urination. Generally, an adult will void approximately 0.8 (about 1/4 gallon) to 2 liters daily (about 1/2 gallon). How much children void varies by age.

However, when an adult voids 3 liters a day or more and a child voids 2 liters a day or more, it is considered polyuria.

Other symptoms can accompany polyuria, such as:

• Excessive thirst
• Frequent urination and urgency (due to peeing greater volumes)
• Incontinence (leaking urine)
• Nocturia (going to the bathroom at night)

It’s important to distinguish between frequent urination and polyuria. Frequent urination and urgency can occur due to other conditions (e.g., a urinary tract or bladder infection) and do not necessarily mean someone is urinating a greater amount of urine.

However, someone with polyuria will go to the bathroom more frequently due to larger volumes of urine.

Frequent urination, especially nocturia, is often associated with polyuria but can also be related to other causes, such as recent bladder surgery, post-radiology fibrosis, bladder stones, and bladder cancer, among other health conditions.

While polyuria is an increased volume of urine, it is not usually painful. Dysuria is painful urination and can be a sign of an underlying health issue, such as a bladder infection.

Medical Causes

There are several causes of polyuria, ranging from drinking too much water to serious health conditions like diabetes mellitus and kidney failure. The following causes of polyuria are the most common.

Diabetes Mellitus

There are two main types of diabetes: type 1 and type 2. Both forms can cause excessive thirst and urination. Individuals with type 1 may also experience nausea and stomach pain.

There is also a type of diabetes that can develop during pregnancy called gestational diabetes. This form of diabetes typically has mild symptoms or no symptoms and goes away after delivery. Most pregnant individuals are tested for this condition during pregnancy.

When someone has diabetes, their bloodstream has too much sugar in it. Typically, the kidneys hold on to sugar and then send it back into the bloodstream. When there’s too much sugar, it comes out in urine.

The increase in sugar in the urine pulls water from the body’s tissues, increasing urine volume. This, in turn, can make an individual dehydrated and feel thirsty, resulting in increased water consumption.

Other signs and symptoms of diabetes include:

• Increased hunger
• Fatigue
• Blurry vision
• Numbness and tingling sensations
• Slow-healing injuries
• Weight loss

Diabetes Insipidus

Diabetes insipidus is different from diabetes mellitus and doesn’t have anything to do with blood glucose levels. Instead, diabetes insipidus and polyuria pertain to arginine vasopressin (AVP), an antidiuretic hormone.

Vasopressin is the hormone that helps your kidneys concentrate urine. It does this by signaling your body to return some of the fluid the kidneys filter back to your bloodstream. When your body doesn’t make enough vasopressin (AVP-deficient), more urine is excreted.

Individuals with diabetes insipidus pee significant amounts of urine. This, in turn, makes them thirsty, and so they also drink large volumes of water.

There are two main types of diabetes insipidus: central and nephrogenic.

Central diabetes insipidus: This type is caused by a lack of AVP secretion due to a neurological condition. It usually develops from a medical or traumatic brain injury.

Nephrogenic diabetes insipidus: This type is due to the failure of the kidney to respond to AVP and is usually inherited.

Sickle Cell Anemia

Sickle cell anemia is an inherited blood disorder affecting hemoglobin in red blood cells. Hemoglobin is a protein that carries oxygen though your body. In sickle cell anemia, the red blood cells are deformed and take on a crescent or “sickle” shape and can block blood flow.

People with this inherited disorder can develop an overactive bladder. Symptoms of overactive bladder include not only frequent urination, but also nocturia, urgency, and urinary incontinence.

Kidney Failure

The kidneys are central to a healthy urinary system. They are responsible for filtering waste and extra water out of the blood to make urine. Kidney failure can cause a range of symptoms, including changes in urine and urination.

Feeling that you have to pee more often, including at night, may indicate your kidneys are no longer working properly. You may also notice blood in your urine or foamy urine. Physical signs of kidney disease may include puffiness around the eyes and swollen ankles and feet. You may also feel tired and have trouble sleeping.

Altered Calcium Levels

High or low levels of calcium in urine may cause you to have to pee more often. Abnormal calcium levels may indicate kidney disease, kidney stones, bone disease, parathyroid disorder, or other conditions.

Other Conditions

Several other conditions can lead to polyuria, especially conditions that can cause arginine vasopressin resistance. When your body experiences vasopressin resistance, it is still producing the hormone but not responding appropriately to it. Examples include amyloidosis and Sjögren’s syndrome.

Amyloidosis is a rare condition with several subtypes. In this condition, too much of a specific protein builds up in the body. Sjögren’s syndrome is an autoimmune disorder that primarily affects the glands that make moisture throughout the body (e.g., those in your mouth and eyes).

Additionally, some individuals with mental health conditions, such as individuals with schizophrenia, may develop psychogenic (psychological origin) polydipsia. Individuals who experience this type of polydipsia will seek out and drink large amounts of water.

Medication Causes

Several medications can alter how much you urinate and potentially lead to polyuria. Two medications most likely to lead to this condition are diuretics and lithium. However, several additional medications can also cause excess urination as a side effect.

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.

Tell your healthcare provider if you’re experiencing frequent urination. Your provider will adjust the dosing of your medications as necessary to avoid unnecessary urination.

Lithium

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.

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

Other Medications

Diuretics and lithium are not the only medications that can cause polyuria. Others include:

• Calcium channel blockers
• Tetracycline
• Selective serotonin reuptake inhibitors (SSRIs)

Additional Causes

There are several additional causes of polyuria. For example, some beverages, such as alcohol and caffeine, can have a diuretic effect, making you pee more. Pregnancy can also cause polyuria, whether due to hormonal changes or as a result of gestational diabetes.

Other reasons for polyuria include excessive protein intake or a hospitalized patient receiving too many IV fluids.

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 a diuretic, even for people who drink it regularly. The diuretic effects of caffeine can decrease over time in people who regularly drink it.

Pregnancy

Needing to pee more 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.

Drinking Excessive Water

You may have to pee a lot simply because you’re drinking a lot of water. Your kidneys can detect this and will filter more water out of the blood as a result, creating more urine. The urinary bladder will fill up more quickly and will need to be emptied more often.

Diagnosis

Polyuria is usually a symptom of another condition. A healthcare provider will look at your current list of medications to see if any may be causing polyuria as a side effect, perform a physical exam, and potentially order lab work or other imaging. They may ask questions like if the polydipsia happened suddenly (acutely) or over time (chronically).

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. To look for diabetes mellitus, a provider may measure the patient’s hemoglobin A1C, a blood test that retroactively measures the average blood glucose levels over the previous two to three months.

They may also order a urine glucose test to see if the body is excreting sugar in the urine, which is a sign of diabetes mellitus.

Diagnostic Tests

To figure out what’s causing polyuria, healthcare providers order a range of tests. Examples of tests include:

Treatment

The most effective treatment for polyuria is aimed at the underlying cause. For example, lithium-induced nephrogenic diabetes insipidus may be treated by altering the lithium dose. Polyuria caused by diabetes mellitus will likely improve once the patient’s blood glucose levels are controlled.

For individuals who experience nocturia, lifestyle measures such as limiting liquids before bed may help. Your provider may also prescribe a medication called desmopressin.

When to See Your Healthcare Provider

Having a day or two of frequent urination may be normal. However, if it’s been going on for several days, contact a healthcare provider for advice.

Also, talk to your healthcare provider if you’re concerned about how medications you’re taking may be affecting urination. Your provider may be able to adjust the dose or switch to a different medication.