The urinary system consists of the kidneys, bladder, the ureters that connect these structures; and the urethra, which carries urine from the bladder to the outside of the body. Diseases or abnormal conditions in other organ systems can disrupt normal urinary function. Disturbances in kidney blood supply, immune system reactions in the kidneys and encroachment on the urinary outflow tract by the prostate gland are common conditions that adversely affect urinary system function.
Normal kidney function depends on an adequate, uninterrupted blood supply. Decreased blood delivery to the kidneys is a leading cause of acute renal failure, notes "The Merck Manual for Healthcare Professionals." Acute heart failure, in which the heart manifests a sudden decline in blood-pumping capacity, typically causes a precipitous fall in blood pressure and an accompanying decrease in the volume of blood supplied to the kidneys. This condition frequently provokes a marked decline in kidney function. Timely restoration of a normal blood pressure and adequate kidney blood supply often reverses acute renal failure in this circumstance.
Abnormalities of the blood vessels that supply the kidneys can also adversely affect renal function. Renal artery stenosis is a condition wherein the blood vessels that supply the kidneys narrow, limiting kidney blood supply. An accompanying decrease in renal function characteristically occurs. Renal artery stenosis is most frequently caused by atherosclerosis, a buildup of fatty plaque deposits within the renal arteries, reports the National Institute of Diabetes and Digestive and Kidney Diseases. Smoking increases the risk for atherosclerosis and renal artery stenosis, which may lead to kidney failure.
The immune system can adversely affect kidney function via an errant attack on the tissues or chronic inflammation. Systemic lupus erythematosus is a chronic autoimmune disease that commonly involves the kidneys. The immune system misidentifies the kidneys as foreign and attacks the delicate renal structures, causing mild to severe kidney damage. The National Kidney Foundation reports that approximately 90 percent of people with lupus have some degree of kidney damage from the illness.
Acute interstitial nephritis is another form of kidney disease caused by a damaging immune system reaction. In a 2003 article published in "American Family Physician," Drs. Charles Kodner and Archana Kudrimot report that certain medications, including nonsteroidal anti-inflammatory drugs, cephalosporin antibiotics and beta lactam antibiotics, can provoke inflammation and injury of the kidney tissues. Prolonged drug exposure may cause kidney scarring and permanent renal impairment.
The prostate gland of the male reproductive system slowly enlarges in adult men. The gland encircles the urinary bladder neck and upper end of the urethra. Overgrowth of the prostate, also known as benign prostatic hyperplasia, can constrict the bladder neck and urethra, impeding urinary outflow. Difficulty passing urine due to prostate enlargement causes a variety of urinary symptoms, including increased frequency of urination, incontinence and waking during the night to urinate.