Urine tests are useful tools for diagnosing many disorders, including those that cause chronic or acute pain. They detect abnormally high or low levels of substances that may indicate a variety of conditions, such as gout, lupus, Reiter’s syndrome, scleroderma, urinary tract infections and prostatitis.

In patients with gout, urine tests may also be used to monitor levels of uric acid and to check for complications such as kidney stones. When complications are detected early, the onset of more serious conditions, such as kidney impairment, may be prevented or delayed.

Urinalysis involves normal urination, and most tests require one sample. Other tests collect urine over a 24-hour period, overnight or during a specific period, such as four hours. Most urine tests involve little or no preparation beforehand, and people can immediately return to their daily activities afterward.

Different urine tests may require different methods of analysis. Urinalysis may include:

• Visual examination
• Test strip examination
• Microscopic examination
• Culture

A urine test (urinalysis) uses a sample of urine to diagnose diseases of the urinary system and other body systems. Urinalysis may be ordered to check for early signs of a disease or disorder, or it may be used to monitor kidney or liver diseases as well as inflammatory illnesses resulting in pain, such as:

• Gout. One of the most painful forms of arthritis.
  
  
• Reiter’s syndrome. A form of reactive arthritis that involves inflammation of joints, the urethra and the lining of the eyes.
  
  
• Systemic lupus erythematosus (SLE). An autoimmune disease involving the skin, joints and internal organs.
  
  
• Scleroderma. An autoimmune connective-tissue disorder characterized by changes in the skin, blood vessels, skeletal muscles and internal organs.
  
  
• Urinary tract infections (UTIs). Bacterial infections in the urinary system are especially common in women.
  
  
• Prostatitis. An acute or chronic inflammation of the prostate gland. This cause of pelvic pain and sexual pain is a common condition in men.
  
  
• Orchitis (inflammation of a testicle) or epididymitis (inflammation of the epididymis, a spermatic duct). These sources of testicular and scrotal pain are often but not always caused by sexually transmitted diseases.
  
  
• Cancers. Urine tests can reveal tumors of the bladder, prostate, kidneys and urethra and a type of blood cancer called multiple myeloma.

Urine tests serve a number of purposes, such as:

• Checking levels of uric acid – the end product of the breakdown of nucleotides as a normal part of metabolism – to monitor treatment of gout.
  
  
• Monitoring for or detecting the presence of substances in urine that indicate kidney disease:
  
  
• • Blood (hematuria) to diagnose or monitor lupus nephritis (kidney disease that is a complication of lupus). Hematuria can also indicate tumors, prostate disorders or a lesion or stones in the urinary tract.
    
    
  • Proteins (microalbuminuria or proteinuria), a possible complication of scleroderma, lupus or diabetes. In addition, proteinuria can be due to preeclampsia, a complication of pregnancy that also involves high blood pressure.
    
    
  • Creatinine (a waste product of the metabolism of creatine, a component of muscle) to diagnose kidney damage.
    
    
• Assessing levels of minerals to help diagnose diseases. For example, elevated levels of calcium in urine can suggest certain types of cancer. Below-normal amounts of phosphate in urine can indicate osteomalacia (a painful condition characterized by weakened bones) or kidney diseases.
  
  
• Finding tumor markers. Several tumor markers, including an enzyme called telomerase, often can reveal bladder cancer. A recently discovered tumor marker called thymosin beta-15 can indicate prostate cancer.
  
  
• Revealing pregnancy. Home pregnancy tests can usually detect pregnancy about two weeks after conception.
  
  
• Indicating menopause. The U.S. Food and Drug Administration has approved a home urine test kit that measures follicle stimulating hormone (FSH) and may show that a woman is in or about to enter menopause.

Urine testing is a simple and easy method of detecting potentially serious conditions early. This allows for treatments that may delay or prevent the onset of more serious complications.

Samples of urine may be taken in several ways:

• Spot sample (also called dipstick method). A single urine sample.
  
  
• 24-hour urine sample. A collection of all urine for a 24-hour period.
  
  
• Overnight urine sample. A collection of all urine excreted between going to sleep at night and waking up in the morning.
  
  
• Timed urine sample. A collection of all urine voided in a specific period (e.g., four hours).

Spot samples provided in a physician’s office should be tested within 15 minutes of collection. Immediately after the sample is taken, the cup is labeled with the date and the patient’s name. Twenty-four-hour samples need to be refrigerated throughout the day and are tested once turned over to the physician’s office or lab. The 24-hour sample is the most accurate way of testing conditions such as microalbuminuria, but because of its inconvenience, a physician may recommend an overnight or timed sample instead.

Different urine tests may require different methods of analysis. Urinalysis may include:

• Visual examination. Tester visually examines the color and clearness of the urine sample. Blood may make the urine appear red or brown. An infection may cause the sample to appear cloudy.
  
  
• Test strip examination. Tester uses a chemically-coated test strip to measure the amount of certain substances in the urine including blood, glucose, creatinine, protein, pH, nitrite, ketones and bilirubin. The test strip is dipped into the urine sample. A chemically coated test pad on the strip will react with the urine and change color accordingly. The test pad is then compared to a color chart of possible results. Test times vary, but most test strips provide results in less than a minute.
  
  
• Microscopic examination. The tester examines a small amount of urine under a microscope. Cells, bacteria, casts (protein substances that can indicate kidney disorders), crystals and other matter are counted and reported as either the number observed or as estimates (e.g., few, moderate or many).
  
  
• Culture. When the presence of bacteria is suspected in the urine, a urine culture may be ordered. A sample of urine is streaked across the surface of one or more lab dishes (Petri dish). The sample is then placed in an incubator that keeps the urine at body temperature. Bacteria will be allowed to grow in the dish so the type of bacteria can be determined. If there is no growth on the dish at the end of 24 hours, the test is considered negative for infection. If yeast or bacteria are present, the organisms are identified and counted. Further testing is then conducted to determine which antibiotics are likely to be effective in treating the infection.

There are many kinds of urine tests that can be used to detect infection, to monitor various inflammatory illnesses resulting in pain, including gout and lupus, and to diagnose complications. These tests include:

• Uric acid test. Uric acid is the end product of the breakdown of nucleotides as a normal part of metabolism. In conjunction with urinalysis of other waste products, it can be used to assess how well the kidneys are functioning. It is a common diagnostic test for gout, a form of arthritis characterized by joint inflammation caused by excessive amounts of uric acid in the blood and deposits of excess uric acid crystals (urates) in and around the joints.
  
  
• Creatinine test. Measures the amount of creatinine in the urine. Creatinine is a waste product removed from the body by the kidneys. Abnormal amounts of creatinine may be a sign of kidney damage. Urinalysis for this waste product is commonly ordered in patients who have rheumatic diseases, such as lupus and scleroderma, to monitor for kidney damage.

Creatinine is sometimes checked with a creatinine clearance test. This compares results of a blood test to a 24-hour urine sample.

• Bilirubin test. Measures the amount of bilirubin – an orange-yellow waste product made from damaged or old red blood cells that have died – in the urine. Bilirubin is normally not detected in the urine. Excessive amounts of bilirubin can cause jaundice (yellowing of the skin and the whites of the eyes). The presence of bilirubin in the urine is often a sign of liver or gallbladder dysfunction, which can cause abdominal pain.
  
  

• Microalbuminuria test. Detects albumin, a protein that prevents fluid from leaking out of blood vessels, nourishes tissues and transports vitamins, hormones, drugs and ions throughout the body. Protein is not normally detectable in urine. The presence of protein in urine (proteinuria) is often an early sign of kidney disease. People with diabetes or certain rheumatic diseases, such as lupus and scleroderma, should be regularly tested for microalbuminuria for early detection and prevention of kidney damage.
  
  
• Nitrite test. Nitrite is normally not detectable in the urine. Nitrite is formed when bacteria changes nitrate in the urine into nitrite. The presence of nitrite in the urine (nitrituria) is often a sign of a urinary tract infection, which results in painful urination.
  
  
• Urine specific gravity test. Measures the concentration of particles in the urine. Abnormally increased or decreased urine specific gravity may indicate a kidney disorder.
  
  
• Urine pH test. Measures the pH (acidity) of the urine. A high level of urine pH may indicate a kidney disorder, including kidney failure.
  
  
• White blood cell test. Checks urine for the presence of white blood cells. The main infection-fighting cells in the body, white blood cells are not normally detectable in the urine. The presence of white blood cells in the urine may indicate a urinary tract infection or prostatitis.

Prior to the urine test, a physician will ask questions about the medical history to determine if the patient is taking any medications or vitamins that will interfere with the test’s results.

Most urine tests require little or no preparation. The physician may instruct the patient to restrict exercise and to reduce or stop taking certain medications or vitamins at some point prior to the test.

Many urine tests involve only a spot (single) sample. Patients will collect their urine sample in a physician’s office or clinic. Patients will receive a cup or other container that they will take into the bathroom. To capture a sample of urine, patients should try to obtain the specimen in midstream, a technique known as “clean-catch.” Preparation for this technique differs depending on the patient’s sex:

• Males. Wipe clean the head of the penis
• Females. Wash the area between the lips of the vagina with soapy water and rinse well.

Patients should not use the first sample upon awakening, but should instead wait to take a later sample. At least three hours should expire between the previous void and the episode used for obtaining the sample. As patients start to urinate, they should let a small amount of the initial urine fall into the toilet bowl. This will help clear the urethra (canal through which urine is discharged) of contaminants. Using a clean container, patients should capture between 1 and 2 ounces (30 to 60 milliliters) of urine before removing the container and finishing urinating into the toilet bowl.

After patients have cleansed, they should give the container and sample to a healthcare provider or assistant.

When obtaining a sample from an infant, an adult should prepare the child by washing the area around the urethral opening. Because infants cannot give voluntary samples, parents will have to rely on a urine collection bag to obtain the sample. This is a plastic bag with an adhesive paper on one end. For boys, the bag is placed over the penis and the adhesive is attached to the skin. For girls, the bag is placed over the labia. The child then wears a diaper over the bag.

The child’s caregiver will need to check frequently to see if the infant has urinated into the bag. Once the urine has been obtained, it is poured into a container and brought to a healthcare provider.

Some urine tests, such as those performed to measure levels of certain waste products (e.g., uric acid, bilirubin, creatinine) require a 24-hour sample rather than a spot sample. To collect a 24-hour urine sample the patient should:

• Get up in the morning of the first day of the test and empty the bladder. The urine should then be discarded in the toilet.
  
  
• Collect all subsequent urine in the provided container for the next 24 hours.
  
  
• Cap the container and keep it in a refrigerator or cool place during the collection period.
  
  
• Get up in the morning of the second day of the test and urinate into the container.
  
  
• Return the container to the physician’s office or a laboratory for analysis.

Afterward patients may resume exercise, medication and vitamin intake according to their physician’s instructions.

It typically takes two or three days for a laboratory to complete a urinalysis. A pathologist will use a microscope to examine the sample for signs of disease, such as bacteria, abnormal epithelial cells (which may indicate cancer), excessive numbers of red blood cells, white blood cells or other abnormal cells. In addition, physicians may order additional tests, such as blood tests, a biopsy, x-rays or an MRI, to verify a diagnosis. Treatment depends on the condition that is diagnosed.

Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about urine tests:

1. What type of urine test is recommended for me?
   
   
2. What does my test involve?
   
   
3. When is the best time to obtain my urine sample?
   
   
4. Do I have to avoid any foods or stop any medication?
   
   
5. What should I do to ensure accurate results?
   
   
6. How long will it take to get the results of my urine test?
   
   
7. What will I learn from the urine test?
   
   
8. Will I need additional tests to confirm diagnosis?
   
   
9. What is the recommended treatment for my condition?
   
   
10. Do I need urinalysis regularly to monitor my condition?