Numerous factors affect the amount and quality of urine produced by the body and the manner in which it is excreted.
Effects of Aging
Diminished ability of kidneys to concentrate urine may result in nocturia.
Hypertrophy of the bladder muscle and thickening of the bladder decreases the ability of the bladder to expand and reduces storage capacity, resulting in increased frequency of urination.
Decreased bladder contractility leading to urine retention and stasis with an increased risk of urinary tract infection (UTI).
Neuromuscular problems, degenerative joint problems, alterations in thought processes, and weakness may interfere with voluntary control of urination and the ability to reach a toilet in time.
Food and Fluid Intake
Dehydration leads to increased fluid reabsorption by the kidneys, leading to decreased and concentrated urine production.
Fluid overload leads to excretion of a large quantity of dilute urine.
Consumption of alcoholic beverages leads to increased urine production due to their inhibition of antidiuretic hormone release.
Ingestion of foods high in water content may increase urine production.
Ingestion of foods and beverages high in sodium content leads to decreased urine formation due to sodium and water reabsorption and retention.
Ingestion of certain foods (e.g., asparagus, onions, beets) may lead to alterations in the odor or color of urine.
Psychological Variables
Individual, family, and sociocultural variables may influence voiding habits.
Patients may view voiding as a personal and private act. The need to ask for assistance may lead to embarrassment and/or anxiety.
Stress may lead to voiding of smaller amounts of urine at more frequent intervals.
Stress may lead to difficulty emptying the bladder due to its effects on relaxation of perineal muscles and the external urethral sphincter.
Activity and Muscle Tone
Regular exercise increases metabolism and optimal urine production and elimination.
Prolonged periods of immobility may lead to poor urinary control and urinary stasis due to decreased bladder and sphincter tone.
Use of indwelling urinary catheters leads to loss of bladder tone because the bladder muscle is not being stretched by filling with urine.
Childbearing, muscle atrophy related to menopausal hormonal changes, and trauma-related muscle damage lead to decreased muscle tone.
Pathologic Conditions
Congenital urinary tract abnormalities, polycystic kidney disease, urinary tract infection, urinary calculi (kidney stones), hypertension, diabetes mellitus, gout, and certain connective tissue disorders lead to altered quantity and quality of urine.
Diseases that reduce physical activity or lead to generalized weakness (e.g., arthritis, Parkinson disease, degenerative joint disease) interfere with toileting.
Cognitive deficits and psychiatric conditions may interfere with ability or desire to control urination voluntarily.
Fever and diaphoresis (profuse perspiration) lead to conservation of body fluids.
Other pathologic conditions, such as congestive heart failure, may lead to fluid retention and decreased urine output.
High blood-glucose levels, such as with diabetes mellitus, may lead to increased urine output due to osmotic diuresis.
Medications
Abuse of analgesics, such as aspirin or ibuprofen, can cause kidney damage (nephrotoxic).
Use of some antibiotics, such as gentamicin, can cause kidney damage.
Use of diuretics can lead to moderate to severe increases in production and excretion of dilute urine, related to their prevention of water and certain electrolyte reabsorption in the renal tubules.
Use of cholinergic medications may lead to increased urination due to stimulation of detrusor muscle contraction.
Use of some analgesics, sedatives, and tranquilizers interferes with urination due to the diminished effectiveness of the neural reflex for voiding because of suppression of the central nervous system.
Use of certain drugs causes changes to the color of urine. Anticoagulants may cause hematuria (blood in the urine) or a pink or red color. Diuretics can lighten the color of urine to pale yellow. Phenazopyridine can cause orange or orange-red urine. Amitriptyline and B-complex vitamins can cause green or blue-green urine. Levodopa (l-dopa) and injectable iron compounds can cause brown or black urine.