What Is Polyuria?

Introduction

Polyuria refers to frequent urination and passing excessive amounts of urine every time a person urinates. Normally, adults pass approximately 1-2 liters of urine per day. However, when there is an excessive urination volume of more than 3 liters a day, it is considered as polyuria. 

Polyuria is one of the most common symptoms of type 1 and type 2 diabetes. People who experience polyuria are also susceptible to severe dehydration, which can significantly affect kidney function if left untreated. In most cases, the symptoms of polyuria often occur at night, which is called nocturia or nocturnal polyuria. 

Causes

The usual cause of polyuria is polydipsia, which is a medical term for excessive drinking or thirst. Excessive fluid intake may include drinking too much water, alcohol, and caffeine. Polyuria is also one of the main signs of diabetes. When kidneys filter the blood to produce urine, they reabsorb blood glucose and return it to the bloodstream. 

In people with diabetes, their blood sugar level is abnormally high. Due to the excessive blood sugar level, some of it ends up in the urine, wherein it draws more water. It then results in passing excessive volumes of urine.

Other Causes of Polyuria

• Pregnancy: Polyuria during pregnancy is a common complaint. It may due to certain changes in the body while pregnant or from a pre-existing health condition.  

• Kidney Disorders: Some forms of kidney diseases can increase a person's urine output. 

• Urinary Incontinence: The loss of bladder control, which is often an embarrassing problem can be mild or severe. 

• Liver Failure: Some patients with liver failure may develop polydipsia that is associated with hepatic encephalopathy. However, they may also experience polyuria due to the loss of renal medullary hypertonicity and low levels of blood urea nitrogen (BUN). 

• Diabetes Insipidus: This disorder causes a water imbalance in the body, which leads to an excessive thirst even after drinking fluids as well as an excessive urine output. 

• Cushing Syndrome: This condition happens when levels of cortisol are abnormally high. The overuse of corticosteroids is one of the most common causes of Cushing syndrome)

• Sickle Cell Anemia: This genetic blood disorder is also called as sickle cell disease. This disorder occurs when a person inherits an abnormal hemoglobin. Hemoglobin is a red blood cell protein molecule that carries oxygen from the lungs to the different tissues of the body. The inherited abnormal hemoglobin usually appears distorted or sickled. 

• Benign Prostatic Hyperplasia or Enlarged Prostate: Commonly observed in men who are 50 years old and above.

• Diuretics: Medications that increase the amount of water excreted from the body.

• Psychogenic Polydipsia: Excessive intake of fluid without any physiological stimuli to drink.

• Hypercalcemia: High levels of calcium in the blood. 

Polyuria may also be experienced after having a CT scan and other tests that involve the injection of a dye into the body. Excessive urination usually occurs the day after the test. Consult your healthcare provider if you continue to experience polyuria.

A person's lifestyle also contributes to excreting excessive urine volume. It may include drinking too much liquid that contains caffeine or alcohol, which are both diuretics. Other diuretics include certain medications for the treatment of edema and high blood pressure. Polyuria may be experienced as a side effect of the following medications:

• Furosemide and bumetanide (loop diuretics)
• Hydrochlorothiazide and chlorothiazide (thiazide diuretics) 
• Eplerenone and triamterene (potassium-sparing diuretics) 

One of the most common causes of polyuria is an uncontrolled diabetes mellitus. Diabetes insipidus is another form of diabetes, in which the urine volume increases due to low levels of the antidiuretic hormone (ADH) or vasopressin in the body. The antidiuretic hormone (ADH) is produced by the pituitary gland and when the levels of ADH are not sufficient, the volume of urine increases. Urine volume also increases if the kidneys are unable to properly control the fluid that passes through them. This condition is called as nephrogenic (renal) diabetes insipidus.

If your healthcare provider suspects that the cause of your polyuria is diabetes, the doctor will check your blood sugar level. Treatment and certain lifestyle changes will be recommended if a form of diabetes is diagnosed. To help control diabetes, the following treatments may be prescribed:

• Oral medications
• Insulin injections
• Changes in dietary intake
• Exercise

Symptoms 

The most common symptom of polyuria, as the name suggests, is frequently passing an excessive amount of urine at regular intervals day and night. Polyuria is also often associated with excessive thirst or polydipsia. Other symptoms of polyuria may include:

• Malaise
• Visual Disturbances
• Loss of Weight
• Fluctuating Blood Pressure
• A consistent headache

How to Relieve Symptoms of Polyuria

Having an excessive urine volume that is not due to any underlying health problem can be treated at home. Your symptoms can be relieved by changing your lifestyle or behavior that leads to frequent and excessive urination. The following tips can help you control polyuria:

• Do not drink any fluid just before bedtime.
• Limit your fluid intake.
• Know and understand certain side effects of your medications. 
• Limit your consumption of alcoholic and caffeinated beverages.

When polyuria is caused by medical conditions, such as diabetes, treatment usually involves addressing the underlying cause. 

When to Seek Medical Help

It is always recommended to seek medical help if you think that you are suffering from polyuria and if it is causing a lot of discomforts, which include:

• Back pain
• Night sweats
• Weight loss
• Fever
• Certain mental disorders
• Leg weakness
• Sudden polyuria

These symptoms may indicate certain medical conditions, such as:

• Kidney infection 
• Diabetes
• Cancer
• Spinal cord disorders

Treatments are prescribed by your healthcare provider to help address your condition. 

Conclusion

Be honest when answering your doctor's questions regarding excessive urination. It may feel awkward to talk about your urination habits, but your doctor can help you better if you cooperate well. In most cases, the outlook of polyuria is good, especially if people do not have serious health conditions.

Certain lifestyle changes may only be needed to help improve your condition. However, serious underlying medical conditions that lead to polyuria may require extensive treatment. Necessary treatments will be discussed by your healthcare provider if the cause of polyuria is diabetes or cancer.