Andrew Siegel, MD 1/8/22
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Today’s entry explains how to do two simple, easy, and free at-home tests to help evaluate and understand your urinary symptoms. One tests your urinary flow rate and the other helps assess urgency and frequency of urination.
Informing your urologist that your urinary stream is not what it used to be and/or that you urinate more frequently than previously is certainly the start to determining the underlying cause and developing a management plan, but it is another dimension entirely if you can come into the office armed with quantitative and objective information derived from these two tests. As a matter of efficiency, if you do these two tests at home prior to your visit, there is a good chance that you will need one less visit to evaluate and manage your problem.
There are two main categories of lower urinary tract symptoms: irritative and obstructive. Obstructive symptoms include urinary hesitancy (stream slow to start), weak stream, intermittency (stop and start stream), prolonged emptying, incomplete emptying, double voiding (needing to urinate a second time to complete urination). Irritative symptoms include urgency (sudden desire to urinate), daytime frequent urination, nighttime frequent urination, and urgency incontinence (urinary leakage).
UROFLOW TEST
This is a helpful test particularly for obstructive urinary symptoms. Supplies needed: a watch with second hands or a stopwatch and a large measuring cup (that holds at least a pint) and a pen.
Do this test only when your bladder is full. Urinate into the measuring cup, recording the time from starting urinating to finishing urinating and the volume voided. Divide the volume by the time, e.g., if you urinate 10 ounces in 20 seconds, 10 ounces/20 seconds = 0.5 ounces/second to get the average flow rate. (Urologists use ccs/sec and since one ounce is 30 cc, the mean flow rate will be 0.5 x 30 = 15 cc/sec.) Bring in this information with you to the office for review.
Urinary flow is dependent upon the ability of the bladder to contract properly and the ability of the urethra to relax properly. Low flow rates are seen with obstruction (prostate enlargement, scar tissue in urethra, dropped bladders causing kinking) and also with impaired bladder contractility, a.k.a. under-active bladder. High flow rates (“super-flows”) occur when there is decreased urethral resistance, often seen in women with stress urinary incontinence.
BLADDER DIARY (VOIDING DIARY)
This test is particularly helpful for people with irritative symptoms. Frequent urination—daytime, nighttime, or both—is an annoying symptom and an extremely common reason for seeing a urologist. The bladder diary is a useful yet underutilized resource to help pinpoint the underlying source of urinary frequency. Its cost is merely the price of a piece of paper, a measuring cup, and a pen, but its yield in terms of facilitating the proper diagnosis is rich. Supplies needed: a pen, a measuring cup and the form below.
It is best to do this on a day that you will be mostly at home. Maintain your normal diet and drinking habits. The diary is done over one 24-hour period, starting with your first morning urination and ending with your last urination prior to your first morning urination of the next day. Urinate into the measuring cup and record the time (make sure you note AM or PM) and volume and repeat this for every urination for the 24 hour time period. After every void, discard the urine. Bring the bladder diary with you to the office for review. Do not bring the measuring cup or your urine! Of note, the average person urinates 4-8 times daily, with a typical full volume of around 10 ounces (300 ml) or so.
TIME (note AM or PM) VOLUME VOIDED
1.___________________________________________________________________
2. __________________________________________________________________
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5. __________________________________________________________________
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10. __________________________________________________________________
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There are 4 major categories of diagnosis based upon the bladder diary, although this is an over-simplification because there can be overlap of symptoms and symptoms are not always consistent:
—Full-volume frequency day and night
—Full-volume frequency only during sleep
—Small-volume frequency day and night
—Small volume frequency only during sleep
Causes of full-volume frequency day and night
- Over-hydration, especially diuretic beverages including caffeine and alcohol
- Diabetes mellitus (“sweet” diabetes) that is poorly controlled
- Certain diabetic medications (SGLT-2 Inhibitors) that eliminate excess blood sugar in the urine, causing a diuretic effect and therefore urinary frequency.
- Diabetes insipidus (“tasteless” diabetes). The pituitary gland produces an important hormone responsible for water regulation–anti-diuretic hormone (ADH)–that gives the message to the kidneys to concentrate urine. Diabetes insipidus is a disease of either kidney origin in which the kidneys do not respond to ADH, or of pituitary origin in which there is deficient secretion of ADH. In either case, lots of urine will be made, resulting in frequent urination, both daytime and nighttime.
- Kidney insufficiency with loss of kidney concentrating ability
- Medications including diuretics, SSRIs (selective serotonin re-uptake inhibitors), calcium blockers, tetracycline and lithium
- Temporary issue from recent high-salt intake with fluid retention: culprits may be prepared foods, soups, breads, cheeses, Chinese, Mexican, Indian foods, etc.
- Dysfunctional thirst mechanism from brain trauma, radiation or surgery causing polydipsia (excessive drinking)
Causes of full-volume frequency only during sleep
- Over-hydration, particularly in evening hours
- Obstructive sleep apnea: This is a hugely prevalent and often unrecognized cause of full-volume nocturnal frequency
- Age-related nocturnal defect in the secretion of ADH or unresponsiveness of the kidneys to the action of ADH
- Congestive heart failure
- Peripheral edema caused by heart, kidney or liver impairment, nephrotic syndrome, malnutrition and venous stasis. These conditions can result in accumulation of fluids in the legs over the course of the day. When lying down to sleep, the fluid (via gravity) returns to the intravascular (within the blood vessels) compartment and is released from the kidneys as urine.
Causes of small-volume frequency only during sleep
- Primary sleep disorders including insomnia, restless leg syndrome, narcolepsy, and arousal disorders (sleepwalking, nightmares, etc.)
Causes of small-volume frequency daytime and during sleep
- Small “functional” bladder capacity: bacterial cystitis, bladder stones, bladder cancer, radiation cystitis, interstitial cystitis, overactive bladder, pelvic floor muscle tension myalgia
- Stone in lower ureter irritating the urinary bladder
- Small “anatomical” bladder capacity: scarring, radiation, other forms of damage
- Prostate enlargement
- Incomplete bladder emptying: prostate enlargement, scar tissue in the urethra, neurologic issues affecting bladder function, bladder prolapse
- Anxiety voiding
- Extrinsic compression on bladder: uterine fibroid, constipation, pelvic mass, pregnancy
Bottom Line: If you are experiencing obstructive and/or irritative urinary symptoms and need to see a urologist in consultation, come to the office “armed” with objective data to help facilitate making the proper diagnosis. Not only will it help your urologist evaluate your symptoms, but it might just save you an additional office visit.
Wishing you the best of health,


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Dr. Andrew Siegel is a physician and urological surgeon who is board-certified in urology as well as in female pelvic medicine and reconstructive surgery. He is an Assistant Clinical Professor of Surgery at the Rutgers-New Jersey Medical School and is a Castle Connolly Top Doctor New York Metro Area, Inside Jersey Top Doctor and Inside Jersey Top Doctor for Women’s Health. His mission is to “bridge the gap” between the public and the medical community. He is a urologist at New Jersey Urology, the largest urology practice in the United States. He is the co-founder of PelvicRx and Private Gym. His latest book is Prostate Cancer 20/20: A Practical Guide to Understanding Management Options for Patients and Their Families.

Video trailer for Prostate Cancer 20/20
Preview of Prostate Cancer 20/20
Andrew Siegel MD Amazon author page
PROSTATE CANCER 20/20 is now available at Audible, iTunes and Amazon as an audiobook read by the author (just over 6 hours).
Dr. Siegel’s other books:
THE KEGEL FIX: Recharging Female Pelvic, Sexual, and Urinary Health
MALE PELVIC FITNESS: Optimizing Sexual and Urinary Health
PROMISCUOUS EATING— Understanding and Ending Our Self-Destructive Relationship with Food
Tags: Andrew Siegel MD, bladder diary, irritative urinary symptoms, obstructive urinary symptoms, uroflow test, urology
January 8, 2022 at 7:49 AM |
Hi, I urinate more than I should, in most cases when working and not drinking water, I urinate after 30 minutes and large volume of urine. At night I sometimes urinate before sleep and urinate again around 5 – 6 am, but sometimes I urinate 4 – 6 times from sleep to wake.
What could be the problem??
January 8, 2022 at 8:11 AM |
Do the bladder diary and bring it in for a urology consultation.
January 8, 2022 at 8:53 AM |
Pls put my husband on this email list:Mrtg119@ aol.comSent from my Verizon, Samsung Galaxy smartphone
January 10, 2022 at 6:06 AM |
I can’t do that for him. He simply has to go to healthdoc13.com and on right margin can sign up for blog to be delivered directly
into his inbox. Thank you.
January 15, 2022 at 7:05 AM |
[…] Last week’s entry showed you how to do a 24-hour bladder diary, a simple at-home test useful to help assess common urological complaints–urinary urgency and frequency. Today’s entry reviews and interprets four patients’ actual bladder diaries. All of the patients had frequent urination as their chief complaint. Before reading through the cases that follow, recall that the average person urinates 6 or so times a day with a typical voided volume of about 8-12 ounces. […]