What is Nocturia?
Nocturia is defined by the International Continence Society (ICS) as “the complaint that the individual has to wake at night one or more times for voiding (i.e. to urinate).” As per the ICS guideline the person void is preceded and followed by sleep.
The word nocturia is a combination of Latin and Greek word. Latin word nox which means night, and Greek word ďýńá means urine. Its may be due to a variety of causes and sometimes it is difficult to know its exact cause.
This symptom has an impact on the health, quality of life and productivity. Normally a person requires 6 to 8 hours of sleep and if they have nocturia, then the sleep gets disturbed and the person feels tired in the morning.
Statistics regarding Nocturia reveal:
- Males are often affected more than females.
- An occurrence of this condition is seen in 50% of both men and women falling in the age group of 60 years and above.
- About 5-15% of people who are 20–50 years old wake up once during the night.
- Nocturia rates are similar for both genders, however, interestingly, studies show that there is a higher prevalence in younger women than younger men and older men than older women.
- There is an increase in the number of voids with an increase in age.
Causes of NocturiaNocturia can both be a symptom and rarely, a condition. The commonest cause of nocturia are as follows:
- Nocturia in a male over the age of 50 years is most commonly due to urinary obstruction caused by enlargement of the prostate gland. However this is often complicated by associated hypertension or diabetes or both. Blood pressure medication can cause fluid retention during the day and excess production of urine in the night that leads to nocturia.
- In diabetes if the blood sugar is high it can act as a diuretic, and results in frequency and nocturia.
- Pregnancy - more so in the first and last trimester of pregnancy.
- Nocturia can also occur by excess consumption of fluids, especially alcohol, particularly in the evenings.
- In Diabetes Insipidus there is excess production of urine due to a hormonal problem and this occurs through out the day and night.
- In women, nocturia may be associated with frequent passing of small amounts of urine due to urinary tract infection.
- Increased calcium in blood can give rise to the symptom of nocturia
- Chronic kidney failure
- Neurological problems such as multiple sclerosis (MS), Parkinson’s disease, or spinal cord compression
- Insomnia may also result in desire to void more often but strictly speaking, this is not nocturia.
The pathological mechanisms resulting in Nocturia are broadly classified into:
- 24 hour Polyuria
- Nocturnal Polyuria
- Reduced Bladder capacity
- Sleep disorders
1. 24 hour Polyuria:
Here the amount of urine produced is more than the normal 24 hour urine output (>40ml/kg body weight). The conditions often resulting in this include:
- Diabetes Mellitus
- Diabetes Insipidus
- Intake of excess water
The amount of urine produced in the night is more than 20% of daily urine output in younger age groups, and more than 33% in elderly patients. The conditions responsible for this include;
- An excess production of Atrial natriuretic peptide
- Renal insufficiency
- Estrogen deficiency
- Sleep apnea syndrome
- Intake of medication (diuretics)
- Intake of caffeine/alcohol
Here the bladder is unable to store the exceeding amount of urine in the night. Some of the conditions that are seen with this mechanism include:
- Benign urinary obstruction due to prostate enlargement
- Neurogenic bladder
- Bladder pain syndrome
- Lower urinary tract calculi
- Lower urinary tract obstruction
Both primary and secondary sleep disorders have been linked to nocturia and conditions like depression needs assessment.
Diagnosis of NocturiaThe diagnosis involves a proper history taking to understand the amount of water intake.
Clinical assessment is done of:
- Lower urinary tract symptoms
- Medications taken
- Any underlying disease
- Any sleep disorders
- Any previous lower urinary tract surgeries
- Assess Conditions like Benign Prostate Hypertrophy
- Assess presence of Overactive bladder
Frequency Volume Chart - Frequency of urination and the volume voided should be charted out using a voiding diary to understand the number of day and night time voiding
- Urine culture and microscopy
- Kidney function, electrolyte levels, glucose and calcium levels
- Rectal examination to rule out local pathologies
- Cardiovascular and Neurological examination to rule out systemic conditions
- Ultrasound of baldder to rule out prostate enlargement and to measure the residual urine that is left in bladder after voiding. High residual urine means that the bladder muscle maybe getting decompensated.
- Overactive bladder requires a special investigation called urodynamics
- Echocardiogram or ECHO of the heart to rule our heart failure
Treatment of NocturiaAfter assessing the mechanism involved the treatment modalities are decided on. These are namely:
- Lifestyle modification by following measures to prevent Nocturia symptoms
- Medications that are prescribed depends on the underlying condition:
- Synthetic analogues of Anti-diuretic hormone like desmopressin that reduce urine production (Desmopressin is approved by FDA for treatment of nocturia)
- Anti-muscarinic agents for destrusor over activity
- Melatonin helps in maintaining circadian rhythm
- In conditions with Benign Prostate Hypertrophy combination therapy may be required with medication for treatment
- Other systemic conditions like diabetes mellitus also require to be addressed with proper medication started if required
Complications of Nocturia
- Nocturia affects the sleep cycle and results in an increased tiredness and fatigue for the person.
- When travelling overnight it can pose as a troublesome symptom due to frequent waking up at night
- Nocturia is generally associated with poor concentration, depression and poor performance due to disturbed sleep. And this can result in:
- Metabolic and endocrine functions of the body maybe affected by the poor sleep
- The person is also economically affected as his/her work productivity decreases and he or she also has to bear the cost of treatment.
- The quality of life of the patient is often affected
Prevention of NocturiaThis symptom can be reduced by the following intervention:
- Restrict the intake of fluids in the evening
- Time the diuretic medications for mornings or at least 6-8 hrs before sleep.
- Take naps in the afternoon
- Voiding of urine before going to sleep
- Use of a bed pan if necessary Use of compression stockings and keeping feet at elevated position helps in reducing fluid accumulation.
- Reduce intake of tea/caffeine/alcohol just before sleep