Polyuria

# Overview
Polyuria is the passage of a large volume of urine in a given period (>= 2.5L/24 hours in adult humans).  It often appears with increased thirst (polydipsia). Various causes of polyuria include

# Causes
- Central diabetes inispidus (CDI)
Idiopathic CDI: the most common cause of CDI
Familial CDI
Wolfram syndrome ( DIDOMAD syndrome)
Congenital hypopituitarism
Septo-optic dysplasia
Surgery/trauma
Cancer (lung cancer, leukemia, lymphoma)
Hypoxic encephalopathy
Infiltrative disorders ( histiocytosis X, sarcoidosis, granulomatosis with polyangiitis)
Post-supraventricular tachycardia
Anorexia nervosa
- Idiopathic CDI: the most common cause of CDI
- Familial CDI
- Wolfram syndrome ( DIDOMAD syndrome)
- Congenital hypopituitarism
- Septo-optic dysplasia
- Surgery/trauma
- Cancer (lung cancer, leukemia, lymphoma)
- Hypoxic encephalopathy
- Infiltrative disorders ( histiocytosis X, sarcoidosis, granulomatosis with polyangiitis)
- Post-supraventricular tachycardia
- Anorexia nervosa
- Nephrogenic diabetes inspidous (NDI)
Hereditary NDI
Lithium
Hypercalcemia
Hypokalemia
Renal disease:
Bilateral urinary tract obstruction
Medullary cystic kidney disease
Amyloidosis
Sjogren's syndrome
Autosomal dominant polycystic kidney disease
Sickle cell disease
Medications:
Cidofovir
Foscarnet
Amphotericin B
Demeclocycline
Ifosfamide
Ofloxacin
Orlistat
Didanosine
V2 receptor antagonists
Gestational diabetes insipidus
Craniopharyngioma surgery
Bardet-biedl syndrome
Bartter syndrome
Cystinosis
- Hereditary NDI
- Lithium
- Hypercalcemia
- Hypokalemia
- Renal disease:
Bilateral urinary tract obstruction
Medullary cystic kidney disease
Amyloidosis
Sjogren's syndrome
Autosomal dominant polycystic kidney disease
Sickle cell disease
- Bilateral urinary tract obstruction
- Medullary cystic kidney disease
- Amyloidosis
- Sjogren's syndrome
- Autosomal dominant polycystic kidney disease
- Sickle cell disease
- Medications:
Cidofovir
Foscarnet
Amphotericin B
Demeclocycline
Ifosfamide
Ofloxacin
Orlistat
Didanosine
V2 receptor antagonists
- Cidofovir
- Foscarnet
- Amphotericin B
- Demeclocycline
- Ifosfamide
- Ofloxacin
- Orlistat
- Didanosine
- V2 receptor antagonists
- Gestational diabetes insipidus
- Craniopharyngioma surgery
- Bardet-biedl syndrome
- Bartter syndrome
- Cystinosis
- Primary Polydipsia
- Osmotic diuresis: Diabetes mellitus

## Causes by Organ System

## Causes in Alphabetical Order
- 3,3-dichlorobenzidine
- Aceruloplasminemia
- Acid-base imbalance
- Acute tubular necrosis
- Adrenal adenoma
- Adrenal cancer
- Adrenal cortex neoplasms
- Adrenal gland hyperfunction
- Adrenal incidentaloma
- Adrenocortical carcinoma
- Aldosteronism
- Alsing syndrome
- Altitude diuresis
- Amelogenesis imperfeca
- Amitraz
- Anorexia nervosa
- Apparent mineralocorticoid excess
- Back tumor
- Bartter syndrome
- BCG vaccine
- Bendrofluazide
- Benign prostatic hyperplasia
- Bladder cancer
- Bladder compression
- Bladder diverticulum
- Boichis syndrome
- Bumetanide
- Caffeine poisoning
- Canagliflozin
- Cardiorespiratory disease
- Cerebral salt-wasting syndrome
- Chemotherapy-induced cystitis
- Chronic glomerulonephritis
- Chronic interstitial nephritis
- Chronic kidney disease
- Chronic renal failure
- Chronic wasting disease
- Combat stress reaction
- Congestive heart failure
- Conivaptan
- Conn-louis carcinoma
- Conn's adenoma
- Conn's syndrome
- Cushing syndrome
- Cushing's syndrome
- Cystinosis
- Cystitis
- Danubian endemic familial nephropathy
- Dapagliflozin
- Dend syndrome
- Diabetes insipidus
- Diabetes mellitus
- Diabetic nephropathy
- Diencephalic syndrome
- Diuretic therapY
- DKA
- Early chronic pyelonephritis
- East syndrome
- Ectopic ACTH syndrome
- Electrolyte abnormality
- Empagliflozin
- Eosinophilic cystitis
- Erdheim-chester syndrome
- Excessive riboflavin
- Excessive vitamin d
- Familial hypopituitarism
- Fanconi syndrome
- Foscarnet sodium
- Froelich's syndrome
- Frusemide
- Generalized anxiety disorder
- Gestational diabetes
- Gitelman syndrome
- Glomerulonephritis
- Gonococcal urethritis
- Goserelin
- Hair-an syndrome
- Heerfordt syndrome
- Hemochromatosis
- Hereditary primary fanconi disease
- Hhns
- Hip cancer
- Hormonal
- Hydrochlorothiazide
- Hyperadrenalism
- Hypercalcemia
- Hypercalcuria
- Hyperglycemia
- Hyperosmolar hyperglycemic nonketotic syndrome
- Hyperosmolarity
- Hyperparathyroidism
- Hyperthyroidism
- Hypervitaminosis a
- Hypervitaminosis d
- Hypokalemia
- Hypokalemic periodic paralysis
- Hypopituitarism
- Hypothalamic dysfunction
- Intermediate cystinosis
- Interstitial cystitis
- Isosorbide
- Juniper tar poisoning
- Juvenile nephronophthisis
- Langerhans cell histiocytosis
- Leukemia
- Lithium
- Machado-joseph disease
- Mannitol
- Medullary cystic kidney disease
- Megalocytic interstitial nephritis
- Membranoproliferative glomerulonephritis
- Migraine
- Multiple endocrine neoplasia
- Nabilone
- Nephrocalcinosis
- Nephrogenic diabetes insipidus
- Nephrolithiasis
- Nephronophthisis
- Nephronophthisis type 1
- Nephropathic cystinosis
- Neurologic damage
- Neurosarcoidosis
- Noctural polyuria syndrome
- Oak poisoning
- Oligomeganephronic renal hypoplasia
- Olivopontocerebellar atrophy type 3
- Osmotic diuresis
- Ovarian cysts
- Overactive bladder
- Panhypopituitarism
- Parathyroid cancer
- Paroxysmal tachycardia
- Pathological water intake
- Pelvic lipomatosis
- Phendimetrazine
- Pheochromocytoma
- Pituitary tumors
- Polycystic kidney disease
- Polydipsia
- Postobstructive uropathy
- Postural orthostatic tachycardia syndrome
- Premenstrual syndrome
- Primary hyperaldosteronism
- Primary tubular proximal acidosis
- Probenecid
- Prostate cancer
- Proximal renal tubular acidosis
- Proximal tubulopathy
- Psychogenic polydipsia
- Pyelonephritis
- Radiation cystitis
- Radiographic contrast media
- Reflux nephropathy
- Reiters syndrome
- Renal cell cancer
- Renal failure
- Renal tubular acidosis
- Renal tubular transport disorders
- Resolving hematoma
- Rib tumor
- Sassoon hospital syndrome
- Secondary bone cancer
- Seizures
- Senior-loken syndrome
- Serratia urinary tract infection
- Sicca syndrome
- Sickle-cell anemia
- Silicon dioxide
- Sodium ferrocyanide
- Sorbitol
- Streptococcal group b invasive disease
- Syndrome of inappropriate antidiuretic hormone
- Tiagabine
- Tolvaptan
- Toni-fanconi syndrome type 1
- Urethral cancer
- Urethritis
- Urinary outflow obstruction
- Urinary stones
- Urinary tract infection
- Uterine fibroids
- Uterine leiomyoma
- Vagina cancer
- Wandering spleen
- Wolfram's disease

# Differential Diagnosis of Polyuria

# Pathophysiology

## Central diabetes inspidus (CDI)
- Results from a deficiency in production, and release of functional AVP, hence respond to  administration of exogenous AVP.
- CDI can be acquired or hereditary. ADH-producing cells' injury in  hypothalamus/pituitary can be idiopathic, or due to trauma or infection.
- Hereditary forms of familial CDI can occur secondary to 66 different mutations of the genes encoding AVP-neurophysin II precursor.

## Nephrogenic diabetes insipidus (NDI)
- It results from an inappropriate renal response to AVP and usually reflects a functional defect in V2R or AQP2 protein.
- Administration of AVP, therefore is not sufficient to rectify the concentration defect. It is more commonly an acquired disease.
- Over 225 different mutations in AVPR2 represent almost 90%  of hereditary NDI cases.

## Diabetes mellitus
- Glucose-induced osmotic diuresis is the major etiology of polyuria in patients with hyperglycemia.

## Primary polydipsia
- It is presumed that a central defect in thirst regulation has an important role in pathophysiology of polydipsia.
- In some polydipsia patients for example, the osmotic threshold for thirst is reduced below the threshold for release of AVP.
- AVP is suppressed by fall in plasma osmolality(because of excessive water intake), and causes rapid excretion of the excess water and continued stimulation of thirst.

# Complications
- Polyuria can result in dehydration, hypernatremia and electrolyte abnormalities if the etiology is solute diuresis.