Most people believe that drug tests detect cocaine within urine by simply measuring the amount of drug traces. This is actually incorrect in most instances.
In fact, drug tests detect cocaine through its ability to interfere with other bodily processes. Here's a more detailed explanation.
When a person uses drugs, they interfere with everyday bodily processes. More specifically, cocaine plays havoc with the ability to create antigen-antibody complexes, which play a massive role in the immune system.
Cocaine use is detected within urine due to a reduced number of antigen-antibody complexes. Each drug test has a scale of the amount of antigen-antibody complexes that should be present within the urine, and if the test reveals a strange amount is present, it will declare a positive test result.
Issues with the test
There are, however, issues with this common form of drug testing as false negatives and positives have been known to occur. Further to this, people have been known to cheat on the drugs test by providing a urine sample from somebody else.
Of course, it's difficult to cheat on a drugs test these days in most instances as there will be an assistant in the bathroom with you to make sure everything is above board.
If a test result is contested as being incorrect, a more advanced (and more expensive) drug test can be administered. This test is known as a gas chromatography, and is much more accurate than a common drugs test.
