What Affects the Test

Reasons you may not be able to have the test or why the results may not be helpful include:

• If you are having your menstrual period.
• Taking medicines, such as diuretics, erythromycin, trimethoprim (Trimpex), or high doses of vitamin C (ascorbic acid) taken with an antibiotic, such as tetracycline.
• Having an X-ray test with contrast material in the past 3 days.
• Not getting urine sample to lab in 1 hour.

What To Think About

• Some urine tests can be done using a home test kit. For more information, see the medical test Ketones or Home Test for Urinary Tract Infections.
• In some cases, the amount of urine you make in 24 hours may be measured. Most adults make about 1qt to 2qt per day. Children make about 0.3qt to 1.6qt per day.
• Other substances that may be checked during a urine test include:
  • Bilirubin. This is a substance formed by the breakdown of red blood cells. It is passed from the body in stool. Bilirubin is not found in urine. If it is present, it often means the liver is damaged or that the flow of bile from the gallbladder is blocked. For more information, see the medical test Bilirubin.
  • Urobilinogen. This is a substance formed by the breakdown of bilirubin. It is also passed from the body in stool. Only small amounts of urobilinogen are found in urine. Urobilinogen in urine can be a sign of liver disease (cirrhosis, hepatitis) that the flow of bile from the gallbladder is blocked.
  • Bence Jones protein. This is an abnormal protein found in the urine of about 50% of people with a rare type of cancer called multiple myeloma. A urine test is often done when multiple myeloma is suspected. The protein test done during a regular urine test does not check for Bence Jones protein.
• Collecting a urine sample from a small child or baby is done by using a special plastic bag with tape around its opening. The bag is placed around the child's genitals until he or she urinates. Then you carefully removed the bag. To collect a urine sample from a very sick baby, a health professional may use a urinary catheter through the urethra or a needle through the baby's belly directly into the bladder (suprapubic tap).
• To lower the chance of contaminating the urine sample with bacteria, a health professional may collect a urine sample by using a urinary catheter. A catheter may be used to collect urine from a person in the hospital who is very ill or who cannot give a clean-catch sample. Using a catheter allows a clean sample to be collected.
• If an abnormal result is found during a urine test, more tests may be done, such as a urine culture, X-ray of the kidneys (intravenous pyelogram [IVP]), or cystoscopy. For more information, see the medical tests Urine Culture, Intravenous Pyelogram (IVP), and Cystoscopy.