What is a hangover?
A hangover is the unpleasant symptoms that you get after drinking too much alcohol. A hangover occurs when your blood alcohol concentration drops, so typically you have a hangover in the morning after a heavy night’s drinking. So you arrive at work with a hangover.
There is a straightforward cause and effect – hangovers are caused by drinking too much alcohol.
The symptoms associated with a hangover
According to the National Institute on Alcohol Abuse and Alcoholism, quoted in alcoholism.about.com a hangover can include some or all of the following class of symptoms.
- Constitutional Fatigue, weakness, and thirst.
- Pain Headache and muscle aches.
- Gastrointestinal Nausea, vomiting and stomach pain.
- Sleep and Biological Rhythm Decreased sleep, decreased deep sleep and increased slow-wave sleep.
- Sensory Vertigo and sensitivity to light and sound.
- Cognitive Decreased attention and concentration.
- Mood Depression, anxiety and irritability.
- Sympathetic Hyperactivity Tremors, sweating and increased pulse and systolic blood pressure. 
Why the symptoms of a hangover are of concern in the workplace
As you can see from symptoms identified by the Mayo clinic, when you have a hangover it is likely that your memory will be affected, as well as your concentration and your fine hand-eye coordination or dexterity. You might have vertigo which causes you to be unsteady on your feet. You might well be drowsy and your visual-spatial skills will also be affected, which means that you have difficulty with the spatial relationships between objects in your field of vision. This would be a particularly significant problem for engineers and assemblers.
For the employer these symptoms are of great concern as they increase the risks of an employee with a hangover causing problems at work. These problems could include
- Difficulty completing tasks
- Falling asleep on the job
- Conflict with colleagues
- Causing accidents through lack of concentration, vertigo or impaired visual-spatial skills
Hangover versus drunkenness
Having a hangover and being drunk on the job are two different things, but the risks in the workplace are not dissimilar. It is also important to remember that the person with a hangover might still have a raised blood alcohol concentration. Therefore, if you suspect that an employee has a hangover, it is advisable to do a breathalyser test. CMM Technology™ supply a wide variety of alcohol testing products.  These range from disposable saliva and breath alcohol testers, through to state-of-the-art digital handheld breathalysers. They also offer a breathalyser calibration service and issue a calibration certificate. In order to undertake breathalyser tests on your employees it is necessary to abide by the legal requirements. CMM Technology™ provide consulting services to assist you with this.
We are all aware of the risks of having drunk employees in the workplace, but we often overlook the risks associated with an employee having a hangover. As an employer it is your responsibility to be aware of these risks and to identify employees who come to work with a hangover.
Drug & Alcohol Testing -> Alcohol Testing. (2010). Retrieved March 16, 2011, from CMM Technology: http://cmm.com.au/drug-alcohol-testing-alcohol-testing-c-43_52.html?osCsid=d99aa78db436bc1e3714c2d36ab92197
Hangovers. (2009, December 17). Retrieved March 24, 2011, from Mayo Clinic: http://www.mayoclinic.com/health/hangovers/DS00649/DSECTION=complications
The Symtoms of a Hangover. (2010, November 25). Retrieved March 23, 2011, from About.com, alcoholism: http://alcoholism.about.com/od/hangovers/a/symptoms.-LvC.htm
 (The Symtoms of a Hangover, 2010)
 (Hangovers, 2009)
 (Drug & Alcohol Testing -> Alcohol Testing, 2010)