Test Overview
A toxicology test checks blood or urine for the presence of drugs.
In rare cases, stomach contents, sweat, or saliva may also be checked.
Drugs can be accidentally or deliberately swallowed, inhaled,
injected, or absorbed through a skin surface or
mucous membrane. These include prescription
medicines, nonprescription medicine (such as aspirin or acetaminophen),
vitamins, nutritional supplements, alcohol, and illegal drugs, such as cocaine
and heroin.
A toxicology test may check for one specific drug or for up to 30
different drugs at once. Testing is often done on a urine
sample instead of blood, because urine tests are usually easier to do than
blood tests and many drugs show up in the urine. Also, traces of a
drug may remain in urine for longer than in blood.