Polyuria Polyuria is excessive or an abnormally large production or passage of urine. Increased production and passage of urine may also be termed diuresis. Polyuria is usually viewed as a symptom or sign of another disorder (not a disease by itself), but it can be classed as a disorder, at least when its underlying causes are not clear. 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.<unk> l polyuria<unk> l polyuria is defined as an increase in urine production during the night but with a proportional decrease in daytime urine production that results in a normal 24-hour urine volume. With the 24-hour urine production within normal limits,<unk> l polyuria can be translated to having a<unk> l polyuria index (NPi) greater than 35% of the normal 24-hour urine volume. NPi is calculated simply by dividing NUV by the 24-hour urine volume. Similar to the inability of control urination, a disruption of arginine vasopressin (ADH) levels has been proposed for<unk> . Compared with the normal patients,<unk>  patients have a<unk> l decrease in ADH level. Other causes of<unk> l polyuria include diseases such as * congestive heart failure * nephritic syndrome * liver failure * lifestyle patterns such as excessive nighttime drinking * sleep apnea increasing obstructive airway resistance. Obstructive sleep apnea sufferers have shown to have increases in renal sodium and water excretion that are mediated by elevated plasma atrial natriuretic hormone (ANH) levels. ANH is released by cardiac muscle cells in response to high blood volume. When activated, ANH releases water, subsequently increasing urine production. Bladder storage Normal human bladder storage capacity varies from person to person and is considered 400 – 600 mL. A bladder storage disorder is any factor that increases the frequency of small volume voids. These factors are usually related to lower urinary tract symptoms that affect the capacity of the bladder. Some patients with<unk>  have neither global nor<unk> l polyuria according to the above criteria. Such patients most likely have a bladder storage disorder that impacts their nighttime voiding or a sleep disorder.<unk> l 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<unk>  cases occur from a combination of causes. Mixed<unk>  is more common than many realise and is a combination of<unk> l polyuria and decreased<unk> l bladder capacity. In a study of 194<unk>  patients: * 7% were determined to solely have<unk> l polyuria * 57% solely had decreased NBC * 36% had a mixed cause of the two Multifactor caused<unk>  is often unrelated to an underlying urological condition. Mixed<unk>  is diagnosed through the maintenance and analysis of bladder diaries of the patient. Assessment of cause contributions are done through formulas.
Nocturia
Polyuria
Polydipsia
Dysuria
Anuria
Hypersthenuria
Oliguria
Crystalluria