urinary tract obstruction

urinary tract obstruction

      blockage or constriction at any point in the urinary tract that impedes the normal flow of urine and causes urine to be retained in the bladder or kidneys. When an obstruction causes urine to become backed up into the kidneys, the condition is known as hydronephrosis. Obstructions in the urinary tract cause distension of the walls of the bladder, ureter, or renal pelvis, depending on the location of the obstruction, which can occur in the urethra, bladder, or ureters.

      Obstructions are classified as congenital or acquired. Congenital blockage usually takes the form of valvelike folds or partitions in the mucous membrane lining the excretory ducts. The most frequent site is the junction of the ureter and the renal pelvis. An obstruction of this nature is symptomless and difficult to diagnose; consequently, a great deal of damage can be done to the kidneys before it is discovered.

      Acquired obstructions are usually caused by malfunction or abnormal changes in the excretory passages. Obstructions can occur in the urethra from stricture of the wall, usually as a result of infections, or, in males, from enlargement of the prostate gland, which surrounds the urethra. When the urethra is blocked, urine backs up in the bladder. The bladder walls become stretched, and the walls of the bladder, ureters, and renal pelvis may thicken. Infections can set in, which may cause further thickening and inflammation in the ureter, bladder, and pelvic walls. Obstruction of the bladder is caused by tumours, by mineral deposits that form stones, by an enlarged prostate, or by neuromuscular disorders. Some degree of dilatation and obstruction of the ureters occurs during a normal pregnancy, caused by the pressure of a growing fetus and by hormones that cause relaxation of muscle tone.

      The major concern in a blockage or obstruction is the backup of fluids into the kidney, which causes the renal pelvis and calyces to become grossly distended. The functioning tissue of the kidneys can be totally destroyed: thickening of the walls of the pelvis and calyces causes pressure on the renal arteries that interferes with blood flow to the kidneys. This speeds up kidney tissue degeneration. Infections commonly complicate the already deteriorating condition. Kidney tubules and structures that produce urine are replaced by fibrous scar tissue. Urine constituents are reabsorbed by the renal veins, tubes, and lymphatic channels, leading to uremia.

      Because complete urinary tract obstruction can lead to renal failure, treatment must be prompt. Analgesics to relieve pain and antibiotics to prevent infection may be given while diagnostic imaging and urine tests are performed; in some cases, a urinary catheter can be pushed past the obstruction into the bladder to allow urine to escape. Complete or recurrent obstruction and obstruction caused by prostate disease often require surgical treatment.

* * *


Universalium. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • Urinary tract infection (UTI) — Infection of the kidney, ureter, bladder, or urethra. Not everyone with a UTI has symptoms. Common symptoms include a frequent urge to urinate and a painful, burning when urinating. More females than males have UTIs. Underlying conditions that… …   Medical dictionary

  • Lower urinary tract symptoms — (LUTS) are a common problem affecting approximately 40% of older men [RoehrbornCG and McConnell JD: Etiology, pathophusiology, epidemiology, and natural history of benign prostatic hyperplasia. Campell s Urology. WB Saunders Co 2002; chapt 38,… …   Wikipedia

  • Urinary retention — with greatly enlarged bladder at CT. ICD 10 R33 ICD 9 …   Wikipedia

  • Urinary catheterization — Intervention ICD 9 CM 57.94, MeSH …   Wikipedia

  • renal system disease — Introduction  any of the diseases or disorders that affect the human excretory system. They include benign and malignant tumours, infections and inflammations, and obstruction by calculi.       Diseases can have an impact on the elimination of… …   Universalium

  • Hydronephrosis — Infobox Disease Name = PAGENAME Caption = DiseasesDB = 6145 ICD10 = ICD10|N|13|0|n|10 ICD10|N|13|3|n|10 ICD9 = ICD9|591 ICDO = OMIM = MedlinePlus = eMedicineSubj = eMedicineTopic = MeshID = D006869 Hydronephrosis is distention and dilation of the …   Wikipedia

  • Medical analysis of circumcision — Numerous medical studies have examined the effects of male circumcision with mixed opinions regarding the benefits and risks of the procedure. Opponents of circumcision say it is medically unnecessary, is unethical when performed on newborns, is… …   Wikipedia

  • Kidney — For other uses, see Kidney (disambiguation). Kidney Human kidneys viewed from behind with spine removed Latin ren Artery …   Wikipedia

  • Bladder stone (animal) — Bladder stones or uroliths are a common occurrence in animals, especially in domestic animals such as dogs and cats. The stones form in the urinary bladder in varying size and numbers secondary to infection, dietary influences, and genetics.… …   Wikipedia

  • Mohamed Ghonim — Ghonim, Mohammed A محمد غنيم Born 17th March, 1939 Mansoura, Egypt Nationality Egyptian Fields …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”