Drug Testing
Reviewed
Also called: Drug Screen, Drugs of Abuse Testing, Substance Abuse Testing, Toxicology Screen, Tox Screen, Sports Doping Tests
A drug test looks for signs of illegal drugs or certain prescription and/or over-the-counter medicines that can be misused. It is usually done with a urine sample, but other samples may be used. The test cannot diagnose a drug use disorder. Results may be positive (drugs found) or negative (no drugs found or very small amount), and a positive result typically requires a confirmatory test. There are no known physical risks, but social, legal, or employment consequences may occur.
Specimen: Urine (most common), blood, saliva, hair, sweat, fingernails, or breath
Urgent safety information
The test may be used in a hospital emergency room if you have signs of a possible drug overdose, which is a time-critical situation. For routine testing, this is not an urgent test.
Why this test may be ordered
- Employment screening (pre-employment or on-the-job)
- Sports doping testing for performance-enhancing drugs
- Monitoring treatment for drug or alcohol use disorder
- Legal evidence (criminal or motor vehicle accident investigation)
- To prevent prescription drug misuse (e.g., opioids for chronic pain)
Preparation and collection
Tell the testing professional about any prescription drugs, over-the-counter medicines, or supplements you are taking. Avoid foods with poppy seeds, as they can show up as opiates in a drug test.
A health care professional or other person may be present during urine collection. For blood, a small needle is used to draw from a vein. For saliva, a swab is rolled in the mouth. For hair, fingernails, sweat, or breath, specific collection methods are used.
There are no known physical risks to having a drug test. However, if drugs show up in your results, it may affect your job, your eligibility to play sports, the outcome of a legal matter, or other parts of your life. Before you take a drug test, make sure you know what you are being tested for, why, and how the results will be used.
Understanding results
A drug test looks for signs of drug use or misuse. It cannot diagnose a drug use disorder. Results are interpreted by a healthcare professional.
- Positive: One or more drugs were found in amounts that suggest drug use or misuse. Limitation: This result may be a false positive. A confirmatory test is required to verify. Next step: A follow-up urine test (confirmatory test) will be performed to check accuracy.
- Negative: Either the drugs tested were not found in your sample, or a very small amount was found that is not enough to count as a positive test result. Limitation: A negative result does not rule out drug use that occurred long before the test or use of drugs not included in the test panel. Next step: No further action is typically needed unless drug use is still suspected.
- A positive result may affect your job, sports eligibility, legal matters, or other aspects of your life.
- False positives can occur due to certain over-the-counter medicines, prescriptions, and foods (e.g., poppy seeds).
- A confirmatory test is needed after a positive initial test to verify accuracy.
- This test cannot diagnose a drug use disorder (addiction).
What to do next
If your result is positive, you will likely have a follow-up confirmatory urine test. If you have questions about how the results will be used, talk with your provider or the organization requesting the test.
- What am I being tested for?
- Why am I being tested?
- How will the results be used?