Investigate whether the amount of urine is normal or whether the urinary frequency is caused by increased urinary output and fluid intake.
Possible organic reasons are to be identified before the symptom is regarded as functional.
Definition
Urinary frequency is subjective.
Urinary frequency should be defined as at least 8 voids in 24 hours, including 2 at night, as it has been found that urination usually takes place less than 8 times in 24 hours.
International Continence Society (ICS) defines nocturia as a need to wake up from sleep once or more often during the night in order to urinate. In practice, however, nocturia cannot be considered significant unless such need arises twice or more often during the night. Nocturnal urination frequency increases with ageing.
Night time is considered as the time between falling asleep and waking up in order to rise for the next day.
If the urinary diary reveals that urine excretion during night time constitutes over 35% of the daily urine volume, the condition is regarded as true nocturnal polyuria Polyuria, in distinction from increased urinary frequency (normal amounts of urine). The first urination in the morning is counted as part of the night urine collection.
Overactive bladder(OAB) is a controversial syndrome considered to consist of various combinations of urinary urgency and increased urinary frequency (> 8 voids/24 hours) or nocturia (> 2 voids/night).
Emotional anxiety
A learned habit
Investigations
History: primary diseases, medication that may affect urination (e.g. diuretics), amount of fluid intake (particularly coffee and alcohol)
Bladder diary and symptom score
DAN-PSS-1 symptom score for men with prostatic hyperplasia
Examination of the genitalia, digital rectal examination of the prostate in men, gynaecological examination in women, palpation of the bladder (in-and-out catheterization if retention is suspected) and, if indicated, an ultrasound examination of the urinary tract Determining the Volume of Residual Urine by Ultrasonography
Chemical urinalysis and bacterial culture of urine, and at discretion e.g. basic blood count with platelet count, CRP, fasting blood glucose, creatinine, TSH, albumin-corrected calcium, PSA test in men over 40 years of age.
Urinary tract ultrasound examination, exclusion of tumours
Treatment
If an organic defect is found to be the cause of urinary frequency, treatment will be targeted at that defect.
Treatment of prostatic hyperplasia; checking the effectiveness of treatment using a voiding diary.
Treatment of overactive bladder (e.g. mirabegron 25-50 mg once daily)
Treatment of chronic prostatitis
Possible treatments for nocturia include fluid restriction in the evening, compression stockings if there is lower limb swelling (cause must be clarified), rest during the day, an NSAID or paracetamol before bedtime, consideration of desmopressin in difficult cases.
Consider physiotherapy/bladder training in cases of idiopathic urinary frequency.
Very severe symptoms should be investigated in specialized care.
References
Serati M, Andersson KE, Dmochowski R ym. Systematic Review of Combination Drug Therapy for Non-neurogenic Lower Urinary Tract Symptoms. Eur Urol 2019;75(1):129-168. [PubMed]
van Haarst EP, Heldeweg EA, Newling DW ym. The 24-h frequency-volume chart in adults reporting no voiding complaints: defining reference values and analysing variables. BJU Int 2004;93(9):1257-61. [PubMed]