In addition to the amount of urine, various release characteristics during urination are also of interest. In the case of bladder emptying disorders, urologists perform uroflowmetry, i.e. urine flow measurement.
All information on the subject of urination characteristics
At a glance
With the aid of a so-called uroflowmeter, the outflow of urine during bladder emptying (micturition) is recorded and graphically displayed in a so-called urine flow curve.
Based on the height and course of this urinary flow curve, the urologist can draw conclusions about certain diseases such as urethral constrictions or prostate enlargement following the examination. The most important measured value is the amount of urine per time unit (s) during a micturition.
The following values are recorded or calculated:
- Urine influence rate (Q) [ml/s]
- Urine flow time (t) [s]
- Maximum urine flow (Qmax) [ml/s]
- Average urine flow (Qave) [ml/s]
- Micturition volume (V) [ml]
- Micturition duration (bladder emptying time) [s]
Urologists usually perform uroflowmetry for the following conditions:
- Incontinence – it is not possible for a patient to retain urine
- Reflux – urine flows from the bladder back into the ureter and possibly even back into the renal pelvis.
- Attenuation of the urine stream
- Temporary interruption of urination (intermittent micturition)
- Disorders at the beginning of urination (micturition start disorders)
- painful urge to urinate with difficulty to urinate – dysuria
- Increased urination at night – Nycturia
- Prolonged urination
- Urge to urinate frequently without increased excretion – Pollakisuria
- residual urine sensation
- Urinary stasis with suspected bladder emptying disorder
- Therapy monitoring after operations on the urethra, prostate or medication for a bladder emptying disorder
- Imperative urge to urinate with or without urge incontinence – sudden, uncontrollable urge to urinate with or without involuntary loss of urine
Following uroflowmetry, the urologist uses ultrasound to check whether there is residual urine in the bladder. If this is the case, the urologist determines exactly how much urine remains in the bladder. Residual urine can lead to inflammations in the bladder and also in the urinary tract and up to the kidneys due to the multiplication of germs.
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- Abrams et al. (1987): Urodynamik für Klinik und Praxis. Berlin Heidelberg New York : Springer
- Geirsson, G. et al. (1999): The bladder cooling reflex and the use of cooling as stimulus to the lower urinary tract. In: J Urol 162, Nr. 6, S. 1890–6
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