Regulation of urine production by ADH and aldosterone
Polyuria is a condition usually defined as excessive or abnormally large production or passage of urine (at least 2.5 or 3 L over 24 hours in adults). Frequent urination is sometimes included by definition, but is nonetheless usually an accompanying symptom. Increased production and passage of urine may also be termed diuresis.
Polyuria often appears in conjunction with polydipsia (increased thirst), though it is possible to have one without the other, and the latter may be a cause or an effect. Psychogenic polydipsia may lead to polyuria.
The most common cause of polyuria in both adults and children is uncontrolled diabetes mellitus, causing an osmotic diuresis. In the absence of diabetes mellitus, the most common causes are excessive secretion of aldosterone due to adrenal cortical tumour, primary polydipsia (excessive fluid drinking), central diabetes insipidus and nephrogenic diabetes insipidus.
Polyuria may also be due to various chemical substances (diuretics, caffeine, ethanol). It may also occur after supraventricular tachycardias, during an onset of atrial fibrillation, childbirth, and the removal of an obstruction within the urinary tract. Diuresis is restrained by antidiuretics such as ADH, angiotensin II and aldosterone.
Cold diuresis is the occurrence of increased urine production on exposure to cold, which also partially explains immersion diuresis.
Substances that increase diuresis are called diuretics.
Substances that decrease diuresis allow more vasopressin or antidiuretic hormone (ADH) to be present in the kidney.
High-altitude diuresis occurs at altitudes above 10,000 ft and is a desirable indicator of adaptation to high altitudes. Mountaineers who are adapting well to high altitudes experience this type of diuresis. Persons who produce less urine even in the presence of adequate fluid intake probably are not adapting well to altitude.
List of causes
- increase in fluid intake, especially water (polydipsia)
- psychogenic polydipsia
- diuretic drugs, osmotic diuresis, (forced diuresis)
- diuretic foods (foods and beverages containing caffeine, such as chocolate, coffee, tea, and soft drinks; hot spicy foods; juices high in acid; alcoholic beverages; protein shakes, etc.)
- interstitial cystitis
- interstitial nephritis
- urinary tract infection - although it more commonly causes frequent passage of small volumes of urine rather than a large volume
- chronic renal failure
- removal of urinary obstruction
- healing acute tubular necrosis
- emphysematous cystitis
- renal tubular acidosis
- Fanconi syndrome/renal glycosuria
- partial obstruction of the urinary tract
- convalescence period of acute renal failure (rebound diuresis)
- Cushing's syndrome
- Addison's disease
- use of a corticosteroid such as prednisone
- Conn's disease (primary aldosteronism)
- diabetes mellitus
- hyperglycaemia (often secondary to diabetes mellitus)
- diabetes insipidus
- congestive heart failure (healing period)
- post supraventricular tachycardia
- postural orthostatic tachycardia syndrome (POTS)
- lupus erythematosus or other connective tissue disease related cystitis
- Sjögren's syndrome
- reactive arthritis/Reiter's syndrome
- high doses of riboflavin (vitamin B2)
- high doses of vitamin C
- cold diuresis
- altitude diuresis
- chronic fatigue syndrome
- hypoxia (see also sleep apnea)
- immersion diuresis
- intestinal obstruction (occurs after toxins begin to be absorbed from the damaged intestine)
- side effect of lithium (see lithium thirst)
- liver failure/ cirrhosis
- pyometra in certain animals or appendicitis in humans
- thefreedictionary.com > polyuria. Citing:
- "Excessive passage" - The American Heritage Medical Dictionary Copyright 2007
- "Excessive production" - Gale Encyclopedia of Medicine. Copyright 2008
- "the formation and excretion" - Saunders Comprehensive Veterinary Dictionary, 3 ed. 2007
- http://www.nlm.nih.gov/medlineplus/ency/article/003146.htm Last Editorial Review: 9/30/2009
- merck.com > Polyuria: A Merck Manual of Patient Symptoms podcast. Last full review/revision September 2009 by Seyed-Ali Sadjadi, MD
- Acknowledgements patient.co.uk > Polyuria By Dr Colin Tidy. Document ID: 2632. Document Version: 21. Document Reference: bgp113. Last Updated: 6 Jul 2009
- MedicineNet.com > Definition of Diuresis Last Editorial Review: 8/20/2002
- thefreedictionary.com > diuresis Retrieved on June 13, 2010
- Hackett, Peter H. Mountain Sickness, The American Alpine Club, 1980. pp. 54, 62)
- eMedicine - Hyperparathyroidism : Article by James LaBagnara