Polyuria is an excessive need to urinate. Excessive urination can be a sign of a number of disorders, including diabetes.

Polyuria that occurs over several days and is not due to medications or an increase in fluid intake may be a cause for concern. Left untreated, it can lead to dehydration, a serious complication of diabetes. 

Polyuria can also be due to many other conditions, including diabetes insipidus, other endocrine disorders, kidney disease, liver disease, urinary tract infection, mineral imbalances, head injury, emotional disorders and Wolfram syndrome. Certain medications can also cause excessive urination.

In people with diabetes, polyuria can trigger other symptoms including increased thirst (polydipsia), weight loss and increased hunger (polyphagia). People experiencing polyuria are encouraged to see their physician for appropriate treatment.

Polyuria, an excessive need to urinate, is often one of the first signs of undiagnosed diabetes. In a person diagnosed with diabetes, it may be a symptom of hyperglycemia caused by control of diabetes. Polyuria can trigger other symptoms associated with uncontrolled diabetes, including an increased thirst (polydipsia), weight loss and increased hunger (polyphagia).

When large amounts of glucose (blood sugar) build up in the bloodstream, the glucose is removed from the body in urine. Additional water is excreted to dilute the glucose. As a result, people begin to urinate more frequently. The excessive urination creates an increase in thirst. As calories and water are lost in the urine, the patient may begin to lose weight. The person may also experience an increase in hunger to compensate for the weight loss.

Urination is the body’s way of eliminating waste products and extra water. The average adult discharges about a quart and a half of urine each day. The amount is based on many factors, including the quantity of fluid and food a person consumes and how much fluid is lost through sweat and breathing. Certain types of medications can also affect the amount of urine a person expels.

Definitions of polyuria vary. In adults, the U.S. National Institutes of Health (NIH) describes it as the release of at least 2.5 liters (2.6 quarts) of urine a day. The Diabetes Insipidus Foundation describes it as the release of about 3.5 quarts (3.3 liters) a day by a 150-pound (68-kilogram) adult.

Polyuria may be a cause for concern. People releasing abnormally large amounts of urine are advised to monitor their intake and output of fluids. When frequent urination occurs over several days, and it cannot be explained by medications or an increase in fluid intake, the condition should be reported to a physician. It may be a sign of a number of diseases and disorders, including diabetes.

Left untreated, excessive urination can result in dehydration. Moderate and severe cases of dehydration can require hospitalization and intravenous fluids. If not treated, dehydration can be life-threatening.

To determine the cause of the polyuria, a physician will inquire about the patient’s medical history and perform a physical examination. Questions about the urination may include:

• How long has there been increased urination?
  
  
• Does the volume of urine remain the same day to day?
  
  
• Does the problem seem worse at any particular time of day?
  
  
• How many times each day is urination needed?
  
  
• Has there been an increase in urination at night?
  
  
• What color is the urine?
  
  
• Has there been any blood in the urine?
  
  
• Has urinary incontinence been a problem?
  
  
• Are there any factors that make the problem worse?
  
  
• Are there any factors that help to relieve the problem?
  
  
• How much fluid is consumed each day?
  
  
• How much fluid containing caffeine or alcohol is consumed each day?
  
  
• Does drinking a large amount of fluid increase the urine volume?
  
  
• Does restricting fluid intake reduce the problem?
  
  
• What medications have been taken?
  
  
• What are the current medications?
  
  
• Is there a family history of diabetes or kidney disease?

• Have there been urinary tract infections?
  
  
• Is the patient experiencing prostate problems?

The physician may also ask if the patient has experienced any other symptoms or signs, including:

• Pain or burning when urinating (dysuria)
• Difficulty urinating or weak flow
• Urinary urgency
• A need to get up at night to urinate (nocturia)
• Abdominal or back pain
• Fever

Symptoms alone are not enough to diagnose the cause of polyuria, because the symptoms may indicate another health problem. A physician suspecting prostate disorders, which are common causes of urinary difficulties in men, will likely perform a physical examination including a digital rectal exam (DRE).

If the suspected cause is diabetes, the physician may order diagnostic tests including:

• Urine tests, such as a urine osmolality test
• Fluid deprivation test
• Glucose test
• Waste product tests, such as blood urea nitrogen and creatinine
• Serum osmolality
• Electrolyte panel
• Other blood tests

A number of diseases and conditions can cause polyuria, including diabetes. Excessive urination may also result from medications or dietary factors, such as the type and amount of fluids being consumed.

In people with diabetes, excessive urination may be a sign of hyperglycemia caused by poor diabetes management or an ineffective diabetes management plan. It is also a symptom of undiagnosed diabetes.

When large amounts of glucose (blood sugar) build up in the bloodstream, the sugar is removed from the body in urine. Additional water is excreted to dilute the glucose. As a result, people begin to urinate more frequently.

A patient may prevent hyperglycemia by following a diabetes management plan that is recommended by a physician, which typically includes a good diet and exercise and may include insulin or antidiabetic agents. When episodes of high glucose occur despite these efforts, a physician may recommend changes to the treatment plan.

The symptoms of diabetes vary from person to person. Diabetes often goes undiagnosed because many of its symptoms seem harmless. It is important for people to see their physician when they experience polyuria or any other symptoms of diabetes. If diabetes is not diagnosed and left untreated, a person with diabetes may faint and lapse into a coma.

Other causes of frequent or excessive urination include:

• Excessive intake of fluids, particularly those containing or alcohol.
  
  
• Age. Nocturnal (nighttime) polyuria is common in elderly people.
  
  
• Medications including diuretics, lithium (used to treat bipolar disorder) and demeclocycline (an antibiotic).
  
  
• Excessive vitamin D.
  
  
• Overactive bladder, a sudden need to urinate followed by a bladder contraction and an involuntary loss of urine.
  
  
• Urinary tract infection.
  
  
• Interstitial cystitis, a bladder disorder caused by chronic inflammation.
  
  
• Kidney failure, nephritis (kidney infection), polycystic kidney disease (disorder involving multiple cysts on the kidneys) or other renal conditions.
  
  
Amyloidosis, a buildup of abnormal proteins that disrupts the function of tissues or organs.


Prostate problems, including enlarged prostate (benign prostatic hyperplasia) or prostate cancer.


Sickle cell anemia, an inherited blood disorder in which hemoglobin is defective.

• Diabetes insipidus, an uncommon disorder unrelated to diabetes mellitus.
  
  
• Wolfram syndrome, a rare genetic disorder that include diabetes mellitus and diabetes insipidus.
  
  
• X-ray tests that use a contrast medium (can cause a temporary increase in urination).
  
  
• Psychogenic polydipsia, a psychological disorder in which a person uncontrollably drinks huge quantities of water.

In addition, polyuria can result from the many other conditions that involve excessive thirst, including additional endocrine disorders, mineral imbalances, liver disease, head injury, burns, excessive bleeding and drug abuse.

The management and treatment of polyuria is entirely dependent on its cause. Once the underlying cause is determined, an appropriate treatment plan can be designed for the individual. A person with polyuria caused by medications or diet may be able to improve the condition with simple changes. However, individuals with diabetes may require changes in their diabetes management plan to achieve better control of their glucose (blood sugar) levels.

The prevention of frequent urination is also directly related to its cause. It may include taking medications, discontinuing medications, lifestyle modification and/or a medical procedure or surgery.

When diabetes is the cause, a patient can help prevent polyuria by keeping glucose levels within the target range. This can be achieved by adhering to a physician–recommended diabetes management plan, including a healthy diet, exercise, and insulin or antidiabetic agents. 

When episodes of high blood glucose (hyperglycemia) occur despite these efforts, a physician may recommend changes to the treatment plan. By controlling glucose, the patient can help prevent the symptoms of unstable diabetes, including the excessive need to urinate.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about polydipsia:

1. How much do I need to be urinating to be diagnosed with polyuria?
   
   
2. Could my polyuria be due to diabetes or to another condition?
   
   
3. Could my medications be causing polyuria?
   
   
4. What could it mean if I have painful urination or other urinary difficulties as well as frequent urination?
   
   
5. What tests for polyuria might I have to undergo, and what do they involve?
   
   
6. What do my test results show?
   
   
7. Does my polyuria require treatment?
   
   
8. If so, what are my options, and which do you recommend?
   
   
9. At what point could my polyuria lead to dehydration or other complications?
   
   
10. How much water should I drink?
    
    
11. Does my polyuria require regular monitoring?
    
    
12. In addition to polyuria, what other signs of diabetes should I watch for?