Most people urinate about 4 or 6 times a day, mainly during the day. Normally, adults urinate between 700 mL and 3 L per day. Excessive urination can refer to:
Frequent urination may be accompanied by a feeling of urgent need to urinate (urinary urgency or bladder urgency). Many patients find that they have polyuria because they have to get up to urinate at night (nocturia). Nocturia can also occur if you drink too much liquid near bedtime, even if you do not drink more than usual.
Some causes of increased urine volume (polyuria) are different from the causes of increased urinary frequency (frequency). However, since many people who produce excessive amounts of urine also need to urinate frequently, these two symptoms often appear together.
The most common causes of increased urinary frequency are:
The most frequent causes of polyuria in both adults and children are:
Treatment with diuretic drugs (that increase the excretion of urine) or intake of substances with a diuretic effect, such as alcohol or caffeine
Diabetes insipidus causes polyuria due to problems with a hormone called antidiuretic hormone (or vasopressin ). The antidiuretic hormone helps the kidney to reabsorb fluid. If an insufficient amount of antidiuretic hormone is produced (a condition called central diabetes insipidus) or if the kidney is not able to respond adequately to the hormone (nephrogenic diabetes insipidus), the patient urinates excessively.
Patients with certain kidney disorders (for example interstitial nephritis or kidney injury caused by sickle cell anemia) may also urinate excessively because these diseases decrease the amount of fluid reabsorbed by the kidneys.
Many patients feel ashamed to discuss problems related to urination with their doctor. Even so, these patients should be evaluated because some disorders that cause an excess of urine are very serious. The following information can help you decide if a doctor’s evaluation is necessary and what to expect during this evaluation.
Certain symptoms and characteristics are a concern in people who urinate excessively. These factors include the following:
If the patient has weakness in the legs should go immediately to the hospital, as it may have a disorder of the spinal cord. Patients with fever and low back pain should see a doctor the same day, as they may have an infection in the kidneys. Patients with other warning signs should see a doctor in one or two days. People without warning signs should make an appointment in the consultation as soon as convenient, usually within a week, although delaying the consultation is generally safe if the symptoms have been developing for weeks or months and are mild.
First, the doctor asks about the patient’s symptoms and medical history and then performs a physical examination. Clinical history and physical examination often suggest the cause of excessive urine volume and tests that may be necessary (see Some causes and characteristics of excessive urination ).
The doctor asks about:
Some findings may provide clues about the cause of the increased frequency of urination. Pain or burning during urination, fever, and low back or flank pain may indicate an infection. The diuretic substance is the most likely cause in patients who drink a large volume of beverages that contain caffeine or who have just begun treatment with diuretics. A prostate lesion may be suffered when there are associated urinary problems, such as difficulty in starting urination, a weak urine stream, and dribbling at the end of urination.