Impairment and Intoxication, what’s the difference?

Impairment and Intoxication, what’s the difference?


Merriam-Webster Dictionary defines intoxication as “the condition of having physical or mental control diminished by the effects of alcohol or drugs.”  The save source definition of impairment is “diminishment or loss of function or ability”.

If we consider the definition stated above, impairment can be the deterioration of a person’s judgment as well as physical ability. This deterioration of physiological and cognitive impairment can certainly be cause by alcohol and can begin at blood alcohol levels below those associated with intoxication. The same could be said for many other substances a person might be using. This could include things like pain relievers, anti-anxiety medications or even antihistamines, antiemetics (Gravol) or cough syrup. Someone can be impaired without looking it. There are also many other factors that could cause impairment. From distracted driving to family or legal problems, if a person is tired or worried, these could all contribute to a level of impairment that could prevent a worker from working safely or making sound decisions. 

Intoxication refers specifically to substance use. It’s usually based on a subjective determination of how one feels the sensation or observes the behavior in another person. It is a condition that follows the administration of a psychoactive substance and results in diminished judgment, cognition, consciousness, behavior or other functions and responses. It is typically associated with “drunkenness” and signs of intoxication can include slurred speech, unsteady gait, increased or decreased activity, disorderly conduct, slowed reactions, insensibility or stupefaction. Impairment is a legal standard, while intoxication is not. 

Intoxication is highly dependent on the type and dose of a substance, a person’s tolerance and other factors. While impairment can also be brought on by substance use, there can be many other non-substance related reasons why a person could be impaired. 

Want to know the difference? We can help with that. 

Daniel Hearn

Junior Consultant, 2BSure Substance Abuse Professional Services

January 2, 2021


Barone Defense Firm, (2018). What’s the difference between impairment and intoxication? Retrieved from,,effects%20of%20alcohol%20or%20drugs.&text=Intoxication%20is%20not%20a%20legal%20standard.

Merriam-Webster dictionary, (n.d.). Definition of intoxication. Retrieved from,,point%20of%20intoxication%20cocaine%20intoxication

Merriam-Webster dictionary, (n.d.). Definition of impairment. Retrieved from,

World Health Organization (The), (2021). Management of substance abuse. Retrieved from,