Most people urinate about 4 to 6 times a day, mostly in the daytime. Normally, adults pass between 3 cups (700 milliliters) and 3 quarts (3 liters) of urine a day. Excessive urination can refer to
An increased volume of urine (polyuria)
A normal volume of urine with the need to go more often (urinary frequency)
Both
Urinary frequency may be accompanied by a sensation of an urgent need to urinate (urinary urgency Urinary Urgency A compelling need to urinate (urgency), which may feel like almost constant painful straining (tenesmus), can be caused by bladder irritation. Uncontrolled loss of urine (incontinence) may occur... read more ). Many people particularly notice polyuria because they have to get up to urinate during the night (nocturia). Nocturia also can occur if people drink too much fluid too close to bedtime, even if they drink no more than normal overall.
(See Overview of Urinary Tract Symptoms Overview of Urinary Tract Symptoms Kidney and urinary tract disorders can involve one or both kidneys, one or both ureters, the bladder, or the urethra, and in men, the prostate, one or both testes, or the epididymis. Problems... read more .)
Causes of Excessive or Frequent Urination
Some of the causes of increased urine volume differ from those of too-frequent urination. However, because many people who produce excessive amounts of urine also need to urinate frequently, these two symptoms are often considered together.
The most common causes of urinary frequency are
Bladder infections Overview of Urinary Tract Infections (UTIs) In healthy people, urine in the bladder is sterile—no bacteria or other infectious organisms are present. The tube that carries urine from the bladder out of the body (urethra) contains no bacteria... read more (the most common cause in women and children)
Noncancerous enlargement of the prostate gland (benign prostatic hyperplasia Benign Prostatic Hyperplasia (BPH) Benign prostatic hyperplasia (BPH) is a noncancerous (benign) enlargement of the prostate gland that can make urination difficult. The prostate gland enlarges as men age. Men may have difficulty... read more —the most common cause in men over 50)
The most common causes of polyuria in both adults and children are
Drinking too much fluid (polydipsia)
Diabetes insipidus
Taking diuretic drugs or substances (which increase the excretion of urine), such as alcohol or caffeine
Diabetes insipidus causes polyuria because of problems with a hormone called antidiuretic hormone (or vasopressin). Antidiuretic hormone helps the kidneys reabsorb fluid. If too little antidiuretic hormone is produced (a condition called central diabetes insipidus Central Diabetes Insipidus Central diabetes insipidus is a lack of the hormone vasopressin (antidiuretic hormone) that causes excessive production of very dilute urine (polyuria). Central diabetes insipidus has several... read more ) or if the kidneys are unable to properly respond to it (nephrogenic diabetes insipidus Nephrogenic Diabetes Insipidus In nephrogenic diabetes insipidus, the kidneys produce a large volume of dilute urine because the kidney tubules fail to respond to vasopressin (antidiuretic hormone) and are unable to reabsorb... read more ), the person urinates excessively.
People with certain kidney disorders (such as interstitial nephritis Tubulointerstitial Nephritis Tubulointerstitial nephritis is inflammation that affects the tubules of the kidneys and the tissues that surround them (interstitial tissue). This disorder may be caused by diseases, drugs... read more or kidney damage resulting from sickle cell anemia Sickle Cell Disease Sickle cell disease is an inherited genetic abnormality of hemoglobin (the oxygen-carrying protein found in red blood cells) characterized by sickle (crescent)-shaped red blood cells and chronic... read more 
) may also urinate excessively because these disorders also decrease the amount of fluid reabsorbed by the kidneys.
Evaluation of Excessive or Frequent Urination
Many people are embarrassed to discuss problems related to urination with their doctor. But because some disorders that cause excessive urination are quite serious, people who urinate excessively should be evaluated by a doctor. The following information can help people know when to see a doctor and what to expect during the evaluation.
Warning signs
In people with excessive urination, certain symptoms and characteristics are cause for concern. They include
Weakness of the legs
Fever and back pain
Abrupt onset or onset during the first few years of life
Night sweats, cough, and weight loss, especially in a person who has an extensive smoking history
A mental health disorder
When to see a doctor
People who have leg weakness should go to the hospital immediately because they may have a spinal cord disorder. People who have fever and back pain should see a doctor within a day because they may have a kidney infection Kidney Infection Pyelonephritis is a bacterial infection of one or both kidneys. Infection can spread up the urinary tract to the kidneys, or uncommonly the kidneys may become infected through bacteria in the... read more . People who have other warning signs should see a doctor within a day or two. People without warning signs should schedule an appointment as soon as is convenient, usually within a few days to a week, although waiting longer is usually safe if symptoms have been developing over weeks or longer and are mild.
What the doctor does
Doctors first ask questions about the person's symptoms and medical history and then do a physical examination. What they find during the history and physical examination often suggests a cause of excessive urination and the tests that may need to be done (see table Some Causes and Features of Excessive Urination Some Causes and Features of Excessive Urination Most people urinate about 4 to 6 times a day, mostly in the daytime. Normally, adults pass between 3 cups (700 milliliters) and 3 quarts (3 liters) of urine a day. Excessive urination can refer... read more ).
Doctors ask about
Amounts of fluid drunk and urinated to determine whether the problem is related to urinary frequency or to polyuria
How long symptoms have been present
Whether any other urination problems are present
Whether the person is taking diuretics (drugs and other substances that increase urine production), including beverages that contain caffeine
Some obvious findings may give clues to the cause of frequent urination. Pain or burning during urination, fever, and back or side pain may indicate an infection. In a person who drinks large amounts of beverages that contain caffeine or who has just started treatment with a diuretic, the diuretic substance is a likely cause. A man who has other problems with urination, such as difficulty starting urination, a weak urine stream, and dribbling at the end of urination, may have a prostate disorder.
Some obvious findings may also give clues to the cause of polyuria. For example, polyuria that starts during the first few years of life is likely caused by an inherited disorder such as central Central Diabetes Insipidus Central diabetes insipidus is a lack of the hormone vasopressin (antidiuretic hormone) that causes excessive production of very dilute urine (polyuria). Central diabetes insipidus has several... read more or nephrogenic diabetes insipidus Nephrogenic Diabetes Insipidus In nephrogenic diabetes insipidus, the kidneys produce a large volume of dilute urine because the kidney tubules fail to respond to vasopressin (antidiuretic hormone) and are unable to reabsorb... read more or type 1 diabetes mellitus Type 1 diabetes Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more .
In women, the physical examination usually includes a pelvic examination and the taking of samples of cervical and vaginal fluid to check for sexually transmitted diseases. In men, the penis is examined for presence of a discharge, and doctors do a digital rectal examination to examine the prostate.
Testing
Doctors do a urinalysis Urinalysis and Urine Culture Urinalysis, the testing of urine, may be necessary in the evaluation of kidney and urinary tract disorders and can also help evaluate bodywide disorders such as diabetes or liver problems. A... read more 
and often urine culture Urinalysis and Urine Culture Urinalysis, the testing of urine, may be necessary in the evaluation of kidney and urinary tract disorders and can also help evaluate bodywide disorders such as diabetes or liver problems. A... read more on most people. The need for other testing depends on what doctors find during the history and physical examination (see table Some Causes and Features of Excessive Urination Some Causes and Features of Excessive Urination Most people urinate about 4 to 6 times a day, mostly in the daytime. Normally, adults pass between 3 cups (700 milliliters) and 3 quarts (3 liters) of urine a day. Excessive urination can refer... read more ). If doctors are not sure whether the person is actually producing more urine than normal, they may collect and measure the amount of urine produced over 24 hours. If people actually have polyuria, doctors measure the blood glucose level. If diabetes mellitus is not the cause of polyuria and no other cause, such as excess intravenous fluids, is clearly responsible, other testing is necessary. The levels of electrolytes and concentration of certain salts (osmolarity) are measured in the blood, urine, or both, often after the person is deprived of water for a time and after the person is given antidiuretic hormone.
Treatment of Excessive or Frequent Urination
The best way to treat excessive urination is to treat the underlying disorder. For example, diabetes mellitus is treated with diet and exercise plus insulin injections and/or drugs taken by mouth. In some cases, people can reduce excessive urination by decreasing their intake of coffee or alcohol. People troubled by awakening at night to urinate (nocturia) may need to reduce fluids before bedtime.
Children with nighttime urination (bedwetting) can also be managed with motivational therapy, in which they are rewarded for practicing behaviors that reduce bedwetting (for example, with stickers on a calendar for going to the bathroom before going to bed). If motivational therapy does not work, urination alarms may then be tried. If other measures fail, doctors may prescribe oral desmopressin to control excessive thirst and urination
Doctors may also adjust the dosage of diuretics that may contribute to excessive urination. Adults with nocturia can be treated with bladder relaxants and medications to prevent bladder spasms. Resistant cases can also be treated with desmopressin.
Essentials for Older People
Older men often urinate frequently because the prostate usually enlarges with age (a condition called benign prostatic hyperplasia Benign Prostatic Hyperplasia (BPH) Benign prostatic hyperplasia (BPH) is a noncancerous (benign) enlargement of the prostate gland that can make urination difficult. The prostate gland enlarges as men age. Men may have difficulty... read more ). In older women, frequent urination is also more common because of many factors, such as weakening of the pelvic supporting tissues after childbirth and the loss of estrogen after menopause. Both older men and older women may be more likely to take diuretics, so these drugs may contribute to excessive urination. Older people with excessive urination often need to urinate at night (nocturia). Nocturia can contribute to sleep problems and to falls, especially if a person is rushing to the bathroom or if the area is not well lit. Treatments directed at benign prostatic hyperplasia include oral drugs and surgery for some cases.
Key Points
Urinary tract infections are the most common cause of urinary frequency in children and women.
Uncontrolled diabetes mellitus is the most common cause of polyuria.
Benign prostatic hyperplasia is a common cause in men over 50.
Excessive intake of caffeine can cause urinary frequency in all people.
