There are diverse reasons why drug tests occur. Some drug tests are for medical reasons and are requested by doctors while others may be requested by an employer to make sure employees are not under the influence while they work. Drugs can be detected in a body when there is testing on bodily fluids such as urine or blood. A commercial drug testing lab can help in the chemical analysis of blood, urine, saliva, hair, or sweat to detect drugs. 

  • Testing for medical reasons: Some conditions may arise wherein a physician may need to know if a person is using illegal drugs or not. This information is needed so that the physician may know how to diagnose or treat a patient. For example, a person showing reduced levels of alertness may be intoxicated or ill. Through drug testing, a physician will be able to accurately determine the problem and make the right medical decisions. 
  • Testing in the workplace: Employees can receive drug tests in their place of work to eliminate issues such as poor performance, safety hazards, or liability.  Employees that use drugs are a safety hazard and are prone to errors which will reduce efficiency and lead to accidents in the workplace. Employers can demand drug tests from their employees when they have legitimate concerns about safety and security. 
  • Testing imposed by the legal system: The judiciary and law enforcement have different reasons why it might request for drug testing such as to determine if a criminal offender is under the influence of drugs. Being intoxicated can affect the crime committed by an individual. Blood alcohol concentration (BAC) is a form of breath analysis used by law enforcement to check if drivers are intoxicated or not.  

The criminal justice system uses drug testing to check the amount of drugs in the body system of a person. A reason for this is because drugs are illegal and monitoring it can help analyze the effectiveness of policies aimed at drug control. 

  • Testing during rehabilitation and treatment:  Drug testing during rehabilitation can help monitor and analyze the drug use of a client. Abstinence is a major requirement in many drug tests and drug testing helps to ensure that the client is not relapsing. Drug testing can act as motivation during treatment or rehabilitation as many persons do not want to be identified as violators. Those who offer drugs to people are less likely to give them to those undergoing drug treatment programs because they do not want to be caught.
  • Testing in schools: More and more young people are being exposed to drugs in the educational system. Drug testing is now done in some schools as a way to be a deterrent or discourage students from abusing drugs. Drug testing in schools helps to identify drug users at an earlier period and ensure that they get treatment. 


Drug testing is the analysis of biological samples through the use of chemical technology to detect the presence of drugs or its by-products. 

  • Urine: This is the most popular method of detecting illicit drugs. The collection of urine samples has benefits which include that it is concentrated, drug materials are high in urine, and collection of urine samples is seen as noninvasive. The problem with this method of drug testing includes the fact that it has a short retrospective period, it can be tampered with, and there might be storage problems. 
  • Blood: Drugs can be identified in blood samples. This form of drug testing can show alcohol concentration levels. This method of drug testing can have issues such as infection, disease, storage, and transportation of blood samples. Blood samples are not stable and they can break down if precautions are not taken. 
  • Hair: Drugs consumed by persons eventually get trapped in their hair and the hair keeps a permanent record of drug use. Lab analysis can reveal the presence of different drugs such as heroin, amphetamines, marijuana, nicotine, cocaine, and barbiturates in hair samples. The problem with the use of hair for drug testing includes that it is seen as an invasion of privacy by some people and hair can be passively contaminated.
  • Sweat and saliva: Sweat and saliva can also be used for drug testing though they have limitations such as time frame and blood concentration. A “sweat patch” can help in drug testing as it is an absorbent pad that can be affixed to the body of a person. The pad absorbs sweat and if a person has drugs in their system the sweat patch will contain it and its metabolites. Saliva testing can be an alternative to urine testing as it is seen as more desirable. 
  • Breath: This technique of drug testing is commonly used to check for alcohol. A Breathalyzer can be used to conduct the testing as it relies on detecting alcohol levels in water vapor. It can also be used to check blood alcohol concentration levels. A reason for the popularity of this method is because it is noninvasive as the skin is not pierced in the quest for body fluids. 

Drug addiction affects many companies and the recognition of drug use in the workplace is integral. Signs of substance abuse include personality change, irritability, disheveled appearance, low performance, unexpected weight loss, the smell of alcohol, and intoxication at events. 

Drug tests can be done randomly or systematically in:

  • Groups of people such as athletes or students.
  • People who are applying for jobs in law enforcement or pilots.
  • People who are involved in accidents.
  • People who attempt suicide
  • People are required to undergo testing as part of a judicial hearing. 

Factors that determine how long a drug stays in the body include the amount used, frequency of use, metabolic rate, physical activity, hydration levels, and the type of the drug. Methods to test for drugs include enzyme immunoassay, radioimmunoassay, fluorescence polarization immunoassay, liquid chromatography, gas chromatography, and rapid slide tests 

Natalia Webster

Natalia Webster is a creative content creator, the author of Boomerang, Liar’s Poker, The New New Thing, Moneyball, The Blind Side, Panic, Home Game, and The Big Short, among other works, lives in Boston, Massachusetts, with her husband, and their three children.