The term drug is used to define a substance that is generally illegal and that produces personality altering symptoms in an individual. The effects of drug use depend on which drug is being consumed. Some drugs cause aggressive behavior while others make the user extremely passive. Many drugs result in reduced inhibitions while others result in increased anxiety, stress and blood pressure. In most countries it is illegal to possess, sell or use drugs. However, some medical establishments use drugs for medical purposes and in such situations the use of drugs is not illegal. Repeated drug use over a period of time is likely to have long lasting effects on the individual. Almost all drugs are addictive to a point where the absence of the drug in the system causes withdrawal symptoms. Drug testing is used to establish the presence of the chemicals in the system which could be used for legal purposes of prosecution.
Drug testing is often conducted by law enforcement agencies when there is a suspicion of drug use. Many parents wish to conduct such tests to establish whether their children have succumbed to the temptation of drug use. Employers, particularly in high stress jobs, tend to randomly test their employees for drugs. People working in jobs where the exposure is high, such as drug enforcement jobs, are likely to be tested as well.
Drug testing accuracy depends on many different factors. The timing of the test is crucial as drugs tend to become less and less detectable as time passes from the moment of last consumption. Bodily fluids such as blood, urine and saliva are commonly used in drug tests. Another factor in drug testing accuracy is the laboratory where the test is conducted. If the laboratory does not follow the strict procedures for testing, it is unlikely that the results will be reliable. Hair samples are often used for testing because they tend to contain traces of the drugs for many days after consumption. This is done to prove consumption and is not done during a drug test conducted on a driver of a vehicle. The accuracy of a saliva drug test is also compromised by the person being tested. If excessive consumption of water takes place, the saliva may be diluted. Consuming mints and using mouthwash may also affect the accuracy of this drug test. The best test for drugs consumed in the recent past is the blood test because it is more difficult to tamper with the blood evidence.