National Institutes of Health
- The primary NIH organization for research on Urine and Urination is the National Institute of Diabetes and Digestive and Kidney Diseases
A service of the U.S. National Library of Medicine 
National Institutes of Health
Urine and Urination
Your kidneys form urine by filtering wastes and extra water from the bloodstream. The waste is called urea. It is carried in the bloodstream to the kidneys. From the kidneys, urine travels down two thin tubes called ureters to the bladder. The bladder stores urine until you are ready to go to the bathroom. It swells into a round shape when it is full and gets smaller when empty. If your urinary system is healthy, your bladder can hold up to 16 ounces (2 cups) of urine comfortably for 2 to 5 hours.
You may have problems with urination if you have
- Kidney failure
- Urinary tract infections
- Prostate enlargement
- Bladder control problems like incontinence or interstitial cystitis
- A blockage that prevents you from emptying your bladder
Some conditions may also cause you to have blood or protein to be in your urine. If you have a urinary problem, see your healthcare provider. Treatment depends on the cause.
NIH: National Institute of Diabetes and Digestive and Kidney Diseases
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Start Here
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Your Urinary System and How It Works(National Institute of Diabetes and Digestive and Kidney Diseases)
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Your Urinary System and How It Works
The top row in the table of contents box contains the following groups:
Basics
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Learn More
, and
Multimedia & Cool Tools
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For group Basics
For group Learn More
For group Multimedia & Cool Tools
The bottom row in the table of contents box contains the following groups:
Research
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Reference Shelf
, and
For You
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For group Research
For group Reference Shelf
For group For You
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Overviews
- Urination Problems(American Academy of Family Physicians)
- Also available in Spanish
- Urine Color(Mayo Foundation for Medical Education and Research)
- Urine Odor(Mayo Foundation for Medical Education and Research)
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Diagnosis/Symptoms
- Collection of a 24-Hour Urine Specimen (Beyond the Basics)(UpToDate)
- Urinalysis(American Association for Clinical Chemistry)
- Urine Culture(American Association for Clinical Chemistry)
- Urine Cytology(Mayo Foundation for Medical Education and Research)
- Urine Metanephrines(American Association for Clinical Chemistry)
- Urine Protein and Urine Protein to Creatinine Ratio(American Association for Clinical Chemistry)
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Urodynamic Testing(National Institute of Diabetes and Digestive and Kidney Diseases)
- Uroflowmetry(American Urological Association)
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Treatment
- Managing Bladder Dysfunction with Products and Devices(American Urological Association)
- Urinary Diversion(American Urological Association)
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Urostomy and Continent Urinary Diversion(National Institute of Diabetes and Digestive and Kidney Diseases)
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Specific Conditions
- Blood in Urine (Hematuria)(Mayo Foundation for Medical Education and Research)
- Dysuria (Painful Urination)(InteliHealth, Harvard Medical School)
- Fainting during Urination (Micturition Syncope): What Causes It?(Mayo Foundation for Medical Education and Research)
- Foamy Urine: What Does It Mean?(Mayo Foundation for Medical Education and Research)
- Frequent Urination(Mayo Foundation for Medical Education and Research)
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Hematuria (Blood in the Urine)(National Institute of Diabetes and Digestive and Kidney Diseases)
- Microscopic Hematuria(American Academy of Family Physicians)
- Also available in Spanish
- Other Causes of Painful Urination(American Academy of Family Physicians)
- Also available in Spanish
- Problems Urinating in Public (Paruresis)(American Urological Association)
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Proteinuria(National Institute of Diabetes and Digestive and Kidney Diseases)
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Urinary Retention(National Institute of Diabetes and Digestive and Kidney Diseases)
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Related Issues
- Urinary Catheterization(InteliHealth, Harvard Medical School)
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Health Check Tools
- Frequent Urination(DSHI Systems)
- Pain During Urination(DSHI Systems)
- Urine Color Change(DSHI Systems)
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Videos
- How the Body Works: Urinary System(Nemours Foundation)
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Clinical Trials
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ClinicalTrials.gov: Dysuria(National Institutes of Health)
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ClinicalTrials.gov: Lower Urinary Tract Symptoms(National Institutes of Health)
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ClinicalTrials.gov: Proteinuria(National Institutes of Health)
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ClinicalTrials.gov: Urination(National Institutes of Health)
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ClinicalTrials.gov: Urination Disorders(National Institutes of Health)
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ClinicalTrials.gov: Urine(National Institutes of Health)
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ClinicalTrials.gov: Dysuria
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Genetics
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Genetics Home Reference: Ochoa syndrome(National Library of Medicine)
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Genetics Home Reference: Ochoa syndrome
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Journal Articles
References and abstracts from MEDLINE/PubMed (National Library of Medicine)
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Dictionaries/Glossaries
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Urologic Diseases Dictionary
(National Institute of Diabetes and Digestive and Kidney Diseases)
- Also available in Spanish
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Urologic Diseases Dictionary
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Directories
- Find a Urologist(American Urological Association)
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Organizations
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National Institute of Diabetes and Digestive and Kidney Diseases
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National Kidney and Urologic Diseases Information Clearinghouse(National Institute of Diabetes and Digestive and Kidney Diseases)
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National Institute of Diabetes and Digestive and Kidney Diseases
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Children
- Blood in the Urine (Hematuria) in Children (Beyond the Basics)(UpToDate)
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How the Body Works: Urinary System
(Nemours Foundation)
- Urination Pain(Nemours Foundation)
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Urine Blockage in Newborns(National Kidney and Urologic Diseases Information Clearinghouse)
- Urine Specimens: Tips to Help Children(American Association for Clinical Chemistry)
- Urine Test: Dipstick(Nemours Foundation)
- Urine Tests(Nemours Foundation)
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Men
- Urinary Dysfunction(Prostate Cancer Foundation)
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Women
- Urine Screen for Sugar and/or Protein(American Association for Clinical Chemistry)
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Patient Handouts
- Clean catch urine sample
- Also available in Spanish
- Cystoscopy
- Also available in Spanish
- Frequent or urgent urination
- Also available in Spanish
- Indwelling catheter care
- Also available in Spanish
- Self catheterization - female
- Also available in Spanish
- Self catheterization - male
- Also available in Spanish
- Suprapubic catheter care
- Also available in Spanish
- Urinary catheters
- Also available in Spanish
- Urinary incontinence products - self-care
- Also available in Spanish
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Urinary Retention(National Institute of Diabetes and Digestive and Kidney Diseases)
- Urination - difficulty with flow
- Also available in Spanish
- Urination - excessive at night
- Also available in Spanish
- Urination - painful
- Also available in Spanish
- Urine - bloody
- Also available in Spanish
- Urine drainage bags
- Also available in Spanish
- Urine odor
- Also available in Spanish
- Urine output - decreased
- Also available in Spanish
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You may also be interested in these related encyclopedia pages:
MEDICAL ENCYCLOPEDIA
- Chloride - urine
- Clean catch urine sample
- Creatinine - urine
- Creatinine clearance
- Cystoscopy
- Cytology exam of urine
- Fractional excretion of sodium
- Frequent or urgent urination
- Indwelling catheter care
- Osmolality - urine
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Osmotic diuresis
Protein - urine
Protein electrophoresis - urine
RBC - urine
Self catheterization - female
Self catheterization - male
Sodium - urine
Suprapubic catheter care
Urinalysis
Urinary casts
Urinary catheters
Urinary catheters - what to ask your doctor
Urinary incontinence products - self-care
Urination - difficulty with flow
Urination - excessive at night
Urination - excessive volume
Urination - painful
Urine - abnormal color
Urine - bloody
Urine 24-hour volume
Urine chemistry
Urine collection - infants
Urine concentration test
Urine culture - catheterized specimen
Urine culture - clean catch
Urine drainage bags
Urine drug screen
Urine nitrogen - urine
Urine odor
Urine output - decreased
Urine pH
Urine specific gravity
Uroflowmetry
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Osmotic diuresis
Languages
Urine and Urination - Multiple Languages
