An employee complains he is not feeling well, and the symptoms include a dry cough, fatigue, muscle and joint pain, a headache, stuffy nose, sore throat, and a flushed face due. An employee complains she is not feeling well, and the symptoms include cough, fatigue, muscle and joint pain, a headache, stuffy nose, sore throat, and a flushed face. It may be the first employee has influenza and should go home to recover. The second person may be using drugs like heroin or cocaine and needs rehabilitation services. How is the employer going to tell the difference between an employee with the flu and one using drugs or alcohol?

The symptoms mentioned are common when someone has the flu. Even after recovering from the flu, the fatigue and cough can linger. To prevent the spread of the flu, the person is advised to stay home, drink fluids, and take over-the-counter medications.1 A person with the flu or recovering from the flu may experience anxiety, nervousness, irritability, sweating, shakiness, loss of appetite, and others. A person using illicit drugs needs to stop using them. However, there will be symptoms of withdrawal if the person has used the drugs or alcohol for an extended period of time. For example, people withdrawing from cannabis can experience common symptoms of irritability, nervousness, anxiety, loss of appetite, sleep difficulties, shakiness, sweating, and others.2

Never Jump to Conclusions

Unfortunately, it is impossible to just look at someone and determine the person is on drugs. Often, the flu symptoms and the symptoms of drug use are nearly identical. Employers who jump to conclusions without evidence are setting themselves up for a Fair Work Australia claim, though it may take the form of accusations of discrimination, employer retribution for some reason, and so on. It is just one of the many protections employers get through fairly administered random and for-cause drug and alcohol testing. However, it is important to remember that the random testing must be truly random. If there is for-cause testing, the reasons for administering the test must be carefully documented.

There are some differences between the symptoms flu and drug use, but they are mostly behavioural. A worker who has the flu will not get it every month and so will not call in sick every month. Employers will see typical behaviour patterns in chronic drug and alcohol users. Employees using substances frequently call in sick on Monday mornings after a weekend of partying or bingeing. They may frequently call in sick, giving a different excuse each time. Work productivity will decline for longer than a few days. A worker who is sick may not be productive whilst getting sick or recovering but will eventually return to full productivity. That is not necessarily true of a drug or alcohol user or abuser.

The Truth is in the Testing

Whilst an employer would not hesitate to tell someone with the flu to "go home," the employer has a greater dilemma if substance use is suspected. For-cause drug and alcohol testing is usually justified when someone acts erratically, presents a clearly presents a safety risk, or admits to using substances. The ideal way to identify employees who are using substances is through the random drug and alcohol testing program.

It may not be possible to easily identify flu symptoms versus symptoms of drug use. However, it is very easy to randomly test employees for drugs and alcohol using the high-quality drug testing supplies and breathalysers offered by CMM Technology. The random testing program should be one component of a broader workforce health and wellness program. The reality is that employers want workers who are healthy and safe, meaning they do not have the flu and are not using illicit drugs or alcohol.


Topic: Influenza – The Flu. (18 December 2013). Queensland Health. Retrieved at

Adam Winstock & Toby Lea. Management of Cannabis Withdrawal. (n.d.). National Cannabis Prevention and Information Centre. Retrieved at