Urine test, urine examination, UA
This test looks at a sample of your urine.
Your doctor can use the results from this test to help diagnose, find, or track many conditions, including:
Metabolic diseases such as phenylketonuria
Kidney problems or infections
Urinary tract infections
Congestive heart failure
A lab can look at a urine sample in different ways:
Visual inspection. If urine looks cloudy, red, or reddish-brown, that may mean you have blood or pus in your urine. Sometimes kidney stones can be seen in the urine. Particular odors from the urine - such as a maple syrup, rotting fish, or a mousy smell - can mean certain diseases.
Chemical screening. When the lab puts urine on specially treated strips of paper, called reagent strips or dipsticks, it can give information on how acidic your urine is and whether it contains blood, protein, or sugar.
Microscopic screening. Checking the urine, particularly solid materials in the fluid, under a microscope can give new information or confirm other findings. For example, microscopic screening can show bacteria, red or white blood cells, and tumor cells in the urine.
Often the lab can measure the specific gravity of the urine sample. This shows how concentrated or diluted your urine is.
Many other tests can be done on a urine sample to help diagnosis various diseases, including urinary tract infections and diabetes.
You may have this test as part of a routine checkup.
You may need this test to find a problem that isn't causing symptoms yet, or your doctor may use it to find the cause of symptoms you are having.
You may also have this test to monitor conditions like diabetes.
Your doctor may order other tests to help make a diagnosis.
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
Urine often contains a number of chemicals and other substances. Urine is usually clear, with a light straw color. The pH, a measurement of its acidity and alkalinity, should be between 4.5 and 8. It's normally free of protein, glucose, and ketones. An exam under the microscope will normally find up to five red blood cells, five white blood cells, and no bacteria.
This test requires a urine sample. Your doctor may ask you to collect the sample the first time you urinate in the morning, because urine is the most concentrated at that time of day. Or you may be asked to collect all the urine you make during 12 or 24 hours. Or you may be asked to provide a sample at your appointment.
In some cases, your doctor may collect the sample by placing a small catheter directly into your bladder. If you're a man, the doctor will put the catheter through the penis and urethra and into the bladder. If you're a woman, he or she will put the catheter through the urethra into the bladder.
Menstrual blood can contaminate a urine sample. Vitamin C supplements, food coloring in candy, and the natural color in beets can affect your results.
These medications can affect your results:
You don't need to prepare for this test. But be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.