A urine drug screen is used to detect illegal and some prescription drugs in the urine.
How the Test is Performed
Before the test, you may be asked to remove all your clothes and wear a hospital gown. You will then be placed in a room where you have no access to your personal items or water. This is so you cannot dilute the sample or use someone else’s urine for the test.
This test involves collecting a “clean-catch” (midstream) urine sample:
- Wash your hands with soap and water. Dry your hands with a clean towel.
- Men and boys should wipe the head of the penis with a moist cloth or disposable towelette. Before cleaning, gently pull back (retract) the foreskin, if you have one.
- Women and girls need to wash the area between the lips of the vagina with soapy water and rinse well. Or, if instructed, use a disposable towelette to wipe the genital area.
- As you start to urinate, allow a small amount to fall into the toilet bowl. This clears the urethra of contaminants.
- Then, in the container you are given, catch about 1 to 2 ounces (30 to 60 milliliters) of urine. Remove the container from the urine stream.
- Give the container to the health care provider or assistant.
- Wash your hands again with soap and water.
The sample is then taken to the lab for evaluation.
How will the Test Feel?
The test involves only normal urination.
Why is the Test Performed?
The test is performed to detect the presence of illegal and some prescription drugs in your urine. Their presence may indicate that you recently used these drugs. Some drugs may remain in your system for several weeks, so the drug test needs to be interpreted carefully.
No drugs in the urine, unless you are taking medicines prescribed by your health care provider.
What Abnormal Results Mean?
If the test result is positive, another test called gas-chromatography mass spectrometry (GC-MS) may be done to confirm the results. The GC-MS will help tell the difference between a false positive and a true positive.
In some cases, a positive test will be a false positive. This can result from interfering factors such as some foods, prescription medicines, and other drugs. Your provider will be aware of this possibility.
Drug screen – urine
Source: MedlinePlus, National Library of Medicine
MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.