A clean catch is a method of collecting a urine sample for various tests, including urinalysis, cytology, and urine culture.

Urine collection - clean catch; Clean catch urine specimen

Children or adults:

After cleaning the genital area, urinate a small amount into the toilet bowl to clear the urethra of any contaminants. Then, collect a sample of urine in a clean or sterile container. About 1 - 2 ounces of urine is needed for a test. Remove the container from the urine stream without stopping the flow. You may finish urinating into the toilet bowl. Return the sample to the health care provider, as directed.

Infants:

A collection device must be attached to the baby to collect the urine.

Thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on your infant. For boys, the entire penis can be placed in the bag and the adhesive attached to the skin. For girls, place the bag over the labia. Diaper the infant as usual, covering and securing the bag. Check the baby frequently and remove the bag after the infant has urinated into it. Active infants may displace the bag, so it may take more than one attempt to obtain the specimen. Drain the urine into a container and give it to the health care provider, as directed.

Do not use antiseptics, as they may prevent bacteria from growing during the culture.

Before urinating, boys and men should clean the head of the penis. Girls and women need to wash the area between the vagina "lips" (labia). The health care provider will give you instructions how to do this. You may be given a special clean-catch kit that contains a cleansing solution and sterile wipes.

If the collection is being taken from an infant, you may need a couple of extra collection bags.

Rarely, infants may have a local skin reaction to the tape used with the collection bags.

The clean-catch urine method is used to prevent bacteria from the penis or vagina from getting into a urine sample. The clean catch can be used for a routine urinalysis, a urine culture, or other urine tests that require pure urine for accurate results.

Normal values will depend on the specific test ordered, for example, whether you've had a urinalysis or urine culture.

If the urine sample was sent for urinalysis, abnormal results may indicate the presence of white blood cells, red blood cells, or excessive amounts of protein.

If the urine sample was sent for urine culture, abnormal results may indicate excessive growth of bacteria, a urinary tract infection, or a bladder infection.

There are no known risks.

This is a common method used to collect urine. You may have a false-negative urine culture if you've recently taken antibiotics.

Urine odor refers to the scent of the fluid excreted during urination. Urine odor varies. However, if you drink enough fluids and are otherwise healthy, urine does not usually have a strong smell.

Changes in urine odor are usually temporary. Such changes are not always a sign of disease. Certain foods and medicines, including vitamins, may affect your urine's odor. For example, asparagus causes a characteristic urine odor.

However, foul smelling urine may be due to bacteria, such as that responsible for urinary tract infections. Sweet smelling urine may be a sign of uncontrolled diabetes or a rare disease of metabolism. Liver disease and certain metabolic disorders may cause musty smelling urine.

Abnormal urine odor may indicate:

• Dehydration (concentrated urine can have an ammonia-like scent)
• Hepatic (liver) failure
• Ketonuria
• Maple sugar urine disease (very rare)
• Phenylketonuria(rare)
• Rectal fistula
• Urinary tract infection

Contact your health care provider if you have fever, chills, burning pain with urination, or back pain along with an abnormal urine odor. These may be signs of a urinary tract infection.

The following tests may be performed:

• Urinalysis
• Urine culture

Patel HP. The abnormal urinalysis. Pediatr Clin North Am. Jun 2006; 53(3): 325-37, v.

Wein AJ. Campbell-Walsh Urology. 9th ed. St. Louis, Mo: WB Saunders; 2007.

A urine pH test measures the acidity of urine.

See also: Acid loading test

pH - urine

A urine sample is needed. For information on collecting a urine sample, see: Clean-catch urine sample

Your health care provider may tell you to stop taking certain drugs that can affect the results of the test.

• Drugs that increase urine pH include acetazolamide, potassium citrate, and sodium bicarbonate.
• Drugs that can decrease urine pH include ammonium chloride, thiazide diuretics, and methenamine mandelate.

Eat a normal, balanced diet for several days before the test.

• A diet high in citrus fruits, vegetables, or dairy products can increase your urine pH.
• A diet high in meat products or cranberries can decrease your urine pH.

The test involves only normal urination, and there is no discomfort.

This test measures how acidic your urine is. Your doctor may order this test to check for changes in your body's acid levels.

It may be done to see if you are at risk for kidney stones. Acidic urine is associated with xanthine, cystine, uric acid, and calcium oxalate stones. Alkaline urine is associated with calcium carbonate, calcium phosphate, and magnesium phosphate stones.

Your doctor may also order this test if you need to take certain medications. Some medications are more effective in acidic or alkaline environments. For example, streptomycin, neomycin, and kanamycin are more effective in treating urinary tract infectionswhen the urine is alkaline.

The normal values range from 4.6 to 8.0.

Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

A high urine pH may be due to:

• Gastric suction
• Kidney failure
• Kidney tubular acidosis
• Urinary tract infection
• Vomiting

A low urine pH may be due to:

• Diabetic ketoacidosis
• Diarrhea
• Starvation

The test also may be performed to investigate:

• Alkalosis
• Interstitial nephritis
• Acidosis
• Sepsis

There are no risks.

Urine pH can be affected by various factors after collection such as leaving the urine standing in an uncovered container. Bacteria usually increase the pH as they break down urea in the urine to ammonia.

Bazari H. Approach to the patient with renal disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 115.

Urine of an abnormal color appears different from the usual straw-yellow color. Abnormally-colored urine may be cloudy, dark, or blood-tinged.

See also: Urine, bloody or dark

Discoloration of urine

Any changes in urine color, or the presence of an abnormal urine color that cannot be linked to the consumption of a food or drug, should be reported to your health care provider. This is particularly important if it happens for longer than a day or two, or you have repeated episodes.

Some dyes used in food may be excreted in the urine, and a wide variety of drugs can discolor the urine.

Cloudy or murky urine is a sign of a urinary tract infection, which may also have an offensive smell. Murky urine may also be caused by the presence of bacteria, mucus, white blood cells or red blood cells, epithelial cells, fat, or phosphates.

Dark brown or clear urine is characteristic of a liver disorder such as acute viral hepatitis or cirrhosis.

Pink, red, or smoky brown urine can be a side effect of a medication or may be caused by the recent consumption of beets, blackberries or certain food colorings. It is also characteristic of a urinary tract disorder in which bleeding occurs such as cystitis, enlarged prostate, kidney or bladder tumor, tuberculosis, bladder stones, kidney infection, Wilms' tumor (in children), or hypernephroma. Hemolytic anemia and porphyria can also cause urine to take on these colors. It may also occur after trauma to the kidneys or urinary tract.

Dark yellow or orange urine can be caused by recent use of laxatives or consumption of B complex vitamins or carotene. Orange urine is often caused by phenazopyridine (used in the treatment of urinary tract infections), rifampin, and warfarin.

Green or blue urine is due to the effect of artificial color in food or drug. It may also result from medications including amitriptyline, indomethacin, and doxorubicin.

• Food (beets, blackberries or other naturally red foods)
• Food dyes
• Certain drugs
• Urinary tract infection
• Liver diseases such as acute viral hepatitis or cirrhosis

Other diseases (not presented in order of likelihood -- some are extremely unlikely):

• Acute tubular necrosis
• Acute unilateral obstructive uropathy
• Alport syndrome
• Carcinoma of the urinary bladder
• Chronic or recurrent urinary tract infection
• Chronic prostatitis
• Endocarditis
• Acute cystitis
• Acute glomerulonephritis
• Chronic glomerulonephritis
• Hepatitis
• Nephrolithiasis(kidney stones)
• Prostate cancer
• Renal cell carcinoma
• Rhabdomyolysis

Make an appointment with your health care provider if you have:

• Clear, dark-brown urine, particularly if accompanied by pale stools and yellow skin and eyes
• Pink, red, or smoky-brown urine, and the color change was not expected (due to a food or medication)
• Abnormal urine color that persists without explanation
• Blood in your urine, even on one occasion

The health care provider will perform a physical exam, which may include a rectal or pelvic exam. You will be asked questions about your medical history and symptoms, including:

• Time pattern
  • When did this begin?
  • Did this begin suddenly?
• Quality
  • What color is the urine?
  • Is it consistently the same color throughout the day?
  • Do you have increased or decreased urination?
  • Can you see blood in the urine?
  • Is there an unusual odor?
• Aggravating factors
  • What medicines do you take?
  • Have you eaten foods such as colored candy, beets, berries, or rhubarb?
• Other
  • What other symptoms do you have? (For example,pain when urinating, abdominal pain,back pain or fever)
  • Are you drinking fewer fluids or have decreased thirst?
  • Do you have a decreased appetite?
  • Have you had any previous urinary problems or kidney problems?
  • Do you have any allergies?

Tests that may be done include:

• Blood tests, including liver function tests, if appropriate
• Clean catch urine sample
• Urinalysis
• Ultrasound of kidneys and bladder

Gerber GS, Brendler CB. Evaluation of the urologic patient: History, physical examination, and the urinalysis. In: Wein AJ, ed. Campbell-Walsh Urology. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 3.

Urine collection is a method of getting a urine sample from an infant for testing purposes. It can be done at home.

Thoroughly wash the area around the urethra. If your health care provider gave you cleansing wipes, use these to clean the infant. Clean from the front to the back on a female infant, and from the tip of the penis down on a male infant.

Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on the infant. For males, place the entire penis in the bag and attach the adhesive to the skin. For females, place the bag over the labia.

Put a diaper securely over the bag. Check your baby often and remove the bag after the infant has urinated into it. For active infants, this procedure may take a couple of attempts -- lively infants can displace the bag.

Drain the urine into a container to take it back to the health care provider.

There is no preparation for the test. If you collect the urine at home, you might need a couple of extra collection bags.

There is no discomfort.

The test is performed to get a urine specimen from an infant.

Normal values depend on what tests will be performed on the urine after it is collected.

There aren't really any risks. Rarely, the infant might get a mild skin rash from the adhesive on the collection bag. Bag urine specimens aren't best for urine cultures because they can become contaminated.

Try to return the specimen to the health care provider as soon as possible.

In children under age 3, the discovery of a urinary tract infection is very important, as it may be a sign of a problem with the structure of the urinary tract. However, even with proper cleansing, collecting urine with a bag is not recommended for evaluation of urinary tract infections. There is a high likelihood of contamination with bacteria from the skin and (in girls) the vagina. In these cases, a catheterized urine sampleis better because it is more accurate.

Catheterized specimen urine culture is a test in which a urine sample is taken by inserting a catheter (a thin rubber tube) through the urethra into the bladder.

Culture - urine - catheterized specimen; Urine culture - catheterization; Catheterized urine specimen culture

A nurse or a trained technician may perform the test. First, the area around the opening of the urethra is thoroughly washed with a germ-killing (antiseptic) solution. A well-lubricated thin rubber tube called a catheter is gently inserted and advanced until it enters the bladder. The urine drains into a sterile container, and the catheter is removed.

Rarely, the health care provider may choose to collect a urine sample by inserting a needle directly into the bladder and draining the urine. However, this is usually only done in infants or to immediately screen for bacterial infection.

The urine is taken to a laboratory to determine which, if any, organisms are present in the urine. Other tests may be done to determine how the organism will respond to medications.

Do not urinate for at least 1 hour before the test. If you don't have the urge to urinate, you may be instructed to drink a glass of water 15-20 minutes before the test. Otherwise, there is no preparation for the test.

There is some discomfort. As the catheter is inserted, you may feel pressure. If you have a urinary tract infection, there may be a painful sensation when the catheter is inserted, due to inflammation of the urethra.

The test is performed:

• To obtain a sterile urine specimen in a person who cannot urinate on their own
• When an infection is suspected in the urinary tract
• When urinary retention is suspected

Tests for organisms that cause infection are performed after the urine is collected. This can also help monitor ongoing infections.

Normal values depend on the test being performed. Normal results are reported as "no growth" and indicate that there is no infection.

A "positive" test indicates organisms that cause urinary tract infection were detected.

There is a slight risk of perforation (hole) in the urethra or bladder from the catheter and a risk of infection.

Rarely, a suprapubic aspirate may be performed if a sample cannot be obtained by other methods. In this method, a needle is inserted through the skin of the lower abdomen into the bladder to withdraw urine.

Blood in your urine, or hematuria, can be classified as microscopic or gross.

• Microscopic hematuria is when there is very little blood in the urine and it can only be seen with a microscope.
• Gross hematuria is when there is enough blood in the urine that you can see it with the naked eye. Usually it turns toilet water pale pink or bright red, or you may just see spots of blood in the water after urinating.

Hematuria; Blood in the urine

In women, blood may appear to be in the urine when it is actually coming from the vagina. In men, what may be mistaken for urinary bleeding is sometimes a bloody ejaculation, usually due to a prostate problem. In some cases, blood in the urine can sometimes be confused with blood from a bowel movement. In any case, you should see a health care provider.

Discoloration from certain drugs, beets, or other foods can mimic blood in the urine.

You may not see blood in your urine. In some cases, it is found microscopically when your doctor checks your urine during a routine exam. Your doctor will follow up on this problem to see if it persists and identify the cause.

When blood is visible to the naked eye, prompt and thorough evaluation is always needed. In children, hospitalization is often necessary to complete the work up.

There are many potential causes of blood in the urine. Often, bloody urine is from a problem in your kidneys or other parts of the urinary tract. If your kidneys, urinary tract, prostate, and genitals turn out to be fine, your doctor may check to see if you have a bleeding disorder.

Kidney and urinary tract causes include:

• Cancer of the bladder or kidney
• Kidney or bladder stones
• Kidney disease following strep throat ( post-streptococcal glomerulonephritis) -- a classic cause of blood in the urine in children
• Kidney failure
• Infection of the bladder, kidney, or urethra
• Inflammation of the bladder, urethra, prostate, or kidney ( glomerulonephritis)
• Injury to the bladder or kidney
• Polycystic kidney disease
• Recent urinary tract procedure such as catheterization, circumcision, surgery, or kidney biopsy

Causes from blood disorders include:

• Bleeding disorders (such as hemophilia)
• Blood clot in the kidneys
• Low numbers of platelets
• Medications including blood thinners (such as warfarin)
• Sickle cell disease

Blood in the urine should never be ignored. Tell your doctor about this symptom and get an appropriate evaluation, especially if you have unexplained weight loss, discomfort with urination, frequent urination, or urgent urination.

Call your doctor right away if:

• You have fever, nausea, vomiting, shaking chills, or pain in your abdomen, side, or back
• You are unable to urinate
• You are passing blood clots in your urine

Also call your doctor if:

• You have pain with sexual intercourse or heavy menstrual bleeding -- the problem may be related to your reproductive organs
• You have urine dribbling, nighttime urination, or difficulty starting your urinary flow -- the problem may be related to your prostate

Your doctor will take a medical history and perform a physical examination. Medical history questions may include:

• When did you first notice blood in your urine?
• What is the underlying color of your urine?
• Do you have any pain with urination?
• Has the quantity of your urine increased or decreased?
• Does your urine have an odor?
• Are you urinating more frequently?
• Do you have an urgent need to urinate?
• What medications are you taking, including over the counter drugs?
• Have you recently eaten foods that may cause discoloration, like beets, berries, or rhubarb?
• Do you have any other symptoms like pain in your back, abdomen, or side? Fever, weight loss, nausea, vomiting, or diarrhea? Nighttime urination? Dribbling? Discharge from penis or vagina? Pain with intercourse?
• Have you had previous urinary problems or kidney problems?
• Do you have any allergies?
• Do you have a history of tobacco use?
• Have you had a recent injury?
• Have you had any recent diagnostic or surgical procedures involving the urinary tract?

Tests that may be done include:

• Abdominal ultrasound
• Antinuclear antibody test for lupus
• Blood creatinine level
• Blood differential
• Complete blood count (CBC)
• CT scan of the abdomen
• Cystoscopy
• Intravenous pyelogram (PVP)
• Kidney biopsy
• Kidney x-rays
• Strep test
• Tests for sickle cell, bleeding problems, and other blood disorders
• Urinalysis
• Urine culture
• 24-hour urine collection for creatinine, protein, calcium

The treatment will depend on the cause of the blood in the urine. If a urinary tract infection is confirmed, antibiotics may be prescribed. If appropriate, pain medications will be given.

Gerber GS, Brendler CB. Evaluation of the urologic patient: History, physical examination, and the urinalysis. In: Wein AJ, ed. Campbell-Walsh Urology. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 3.

Decreased urine output is defined as producing less than 500 milliliters of urine in 24 hours.

Oliguria

Although a significant decrease in urine output may indicate a serious, even life-threatening condition, adequate urine output can be restored with prompt medical treatment.

• Dehydration due to vomiting, diarrhea, or fever, with a lack of adequate fluid intake
• Total urinary tract obstruction, such as from an enlarged prostate
• Severe infection or any other medical condition leading to shock
• Use of certain medications such as anticholinergics, methotrexate, and diuretics

Follow prescribed fluid regimens and measure urine output as directed.

Contact your health care provider if you have:

• A noticeable and consistent decrease in urine output
• Vomiting , diarrhea, or high fever and are unable to replace fluids by mouth
• A decrease in urine output associated with dizziness, lightheadedness, or rapid pulse

The health care provider will perform a physical exam and ask questions about your medical history and symptoms, including:

• Time pattern
  • When did this begin?
  • Did it occur suddenly?
  • Has it rapidly become worse?
• Quality
  • How much do you drink each day?
  • Does drinking more increase your urine output?
  • How much urine do you produce each day?
  • What color is the urine?
• Aggravating factors
  • Has there been fever?
  • Has there been diarrhea?
  • Has there been vomiting? With or without nausea?
  • Is thirst decreased?
  • What other symptoms do you have?
• Other
  • What medications do you take?
  • Do you have any allergies?
  • Do you have access to adequate fluids?
• Medical history
  • Have you had any recent injuries such as burns?
  • Have you been sick?
  • Do you have a history of a problem with your kidneys or bladder?

Tests that may be done include:

• Blood studies to monitor electrolytes and kidney function
• CT (cat) scan of the abdomen
• Intravenous pyelogram (IVP)
• Renal scan
• Abdominal ultrasound
• Urine tests, including tests for infection

Gerber GS, Brendler CB. Evaluation of the urologic patient: History, physical examination, and the urinalysis. In: Wein AJ, ed. Campbell-Walsh Urology. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2007: chap 3.

Molitoris BA. Acute kidney injury. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 121.