Such patients most likely have a bladder storage disorder that impacts their nighttime voiding or a sleep disorder. Nocturnal bladder capacity (NBC) is defined as the largest voided volume during the sleep period.Decreased NBC can be traced to a decreased maximum voided volume or decreased bladder storage. Decreased NBC can be related to other disorders such as:

benign prostatic hyperplasia (BPH), also known as prostate enlargement
neurogenic bladder dysfunction
learned voiding dysfunction
anxiety disorders
urinary tract infection
certain pharmacological agents. Mixed cause
A significant number of nocturia cases occur from a combination of causes. Mixed nocturia is more common than many realise and is a combination of nocturnal polyuria and decreased nocturnal bladder capacity. In a study of 194 nocturia patients:
7% were determined to solely have nocturnal polyuria
57% solely had decreased NBC
36% had a mixed cause of the twoMultifactor caused nocturia is often unrelated to an underlying urological condition. Mixed nocturia is diagnosed through the maintenance and analysis of bladder diaries of the patient. Assessment of cause contributions are done through formulas. Management
Lifestyle changes
Although there is no cure for nocturia, many actions can manage the symptoms. Prohibiting caffeine and alcohol intake. Both are diuretic. Beverage consumption regulation. In regard to nocturia, this specifically means avoiding consuming fluids for three or more hours before bedtime so giving the bladder less fluid to store overnight. This especially helps people with urgency incontinence. However, one study regarding geriatric patients showed that it reduced voiding at night by only a small amount and is suboptimal for managing nocturia in older people.
Global polyuria
Global polyuria is the continuous overproduction of urine that is not only limited to sleep hours. Global polyuria occurs in response to increased fluid intake and is defined as urine outputs of greater than 40 mL/kg/24 hours. The common causes of global polyuria are primary thirst disorders such as diabetes mellitus and diabetes insipidus (DI). Urination imbalance may lead to polydipsia or excessive thirst to prevent circulatory collapse. Central diabetes insipidus is caused by low levels of Vasopressin (also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin). ADH is produced in the hypothalamus and stored in and released from the posterior pituitary gland. ADH increases water absorption in the collecting duct systems of kidney nephrons, subsequently decreasing urine production. ADH regulate hydration levels in the body. that helps regulates water levels. In nephrogenic DI, the kidneys do not respond properly to the normal amount of ADH.Diagnosis of DI can be made by an overnight water deprivation test. This test requires the patient to eliminate fluid intake for a fixed period of time, usually around 8–12 hours. If the first morning void is not highly concentrated, the patient is diagnosed with DI. Central DI usually can be treated with a synthetic replacement of ADH, called desmopressin. Desmopressin is taken to control thirst and frequent urination. Although there is no substitute for nephrogenic DI, it may be treated with careful regulation of fluid intake.