The test is done to detect the presence of illicit drugs and some prescription drugs in your urine. Their presence indicates that you recently used these drugs. Some drugs can remain in your system for several weeks, so the screening test must be interpreted carefully.
Common types of drug tests
Urine test, also known as urinalysis, is a procedure that requires one to provide a urine sample. Either one of a test card is used on site for immediate results, or the sample is sent to a laboratory for gas chromatography or mass spectrometry, also known as GCMS. It is known as high-performance liquid chromatography or immunoassay analysis. Sample substitution or adult have become a major problem in the United States, due to the prevalence of synthetic or drug-free urine and a wide range of adulterants on the Internet. Some people try to pass a urine test by drinking plenty of water. However, a sufficiently diluted sample may be rejected due to its light color. Too clear samples can be marked and the specific gravity test, but if the sample does not pass the specific gravity test,
Hair drug testing is fairly accurate and can go back 6 months or more. It shows controlled substances that are used in this time frame. As the hair grows out, they use medicines that are locked in the hair shaft, so the larger the hair, the longer back in the laboratory person's drug history they can detect. Most legitimate testing facilities only use hair within about 3-5 cm of the scalp, and discard the rest. This limits the detection history to approximately 90 days, depending on the person's hair growth rate. Some people try to get around this by shaving their heads. In the absence of the required amount of hair on the scalp, Body hair can be used as an acceptable substitute for results. Also, for the pre-employment hair test, failure to obtain a sample may be grounds for not recruiting the individual drug abuse suspect.
Drug Saliva Screen and Oral Fluid Based Drug Screening - Oral fluid based drug tests can usually detect usage during the previous days. Drug tests based on oral fluids or salivation are becoming more frequent due to their convenience and the fact that they cannot be adulterated. Furthermore, in place of oral based testing, in particular, they allow the execution of randomized testing programs, proven to be the most effective type of drug detection. Oral fluid-based tests are as accurate as urine and can be obtained from quality providers in the United States. The test is generally performed by employers, either for pre-employment, random, post-accident, reasonable suspicion, or return to work tests.
Sweat drug screen are patches attached to the skin to collect sweat over a period of time, most commonly 10-14 days. These are used almost exclusively by child protective services, probation departments, and other government institutions related to drug use for long periods, especially when urinalysis is not practical. The patches have security features that prevent them from being covertly removed and then reapplied without the knowledge of the testing agency, and at the end of the trial period, the patch is removed by a probation officer or social worker and they are sent to the laboratory for analysis. If the person has used drugs during the period that the patch was in place, they go to a positive result for the drug. This type of testing has fallen out of favor with government agencies, due to documented problems with some medications.