Recognizing Intoxication and Impairment
Impairment is a spectrum, not a number
There is no single BAC at which a person suddenly looks drunk, and legal limits are driving thresholds, not safe-serving thresholds. Impairment begins well below any legal limit and shows up first in judgment, inhibition, and divided attention. Your job is to observe behavior and drink count over time, not to estimate a number.
Four cue categories to scan
- Speech: slurring, rambling, repetition, unusually loud or unusually quiet.
- Motor control: stumbling, swaying, bumping furniture, fumbling money or a phone, spilling, missing a chair.
- Appearance: bloodshot or glassy eyes, flushed face, disheveled clothing, sweating, a drink held loosely.
- Behavior and mood: overly friendly, overly loud, tearful, irritable, aggressive, inappropriate comments, sudden mood shifts, forgetting how many drinks they have had.
Track cues across categories rather than leaning on one gesture. A person who is naturally clumsy is not necessarily intoxicated, but clumsiness plus slurred speech plus a mood shift is a pattern.
Traps that appear in questions
- The high tolerance trap: an experienced drinker may show few outward signs at a BAC that would floor someone else. Tolerance does not make service safe.
- The walk-straight trap: coordination can survive longer than judgment. Someone who can walk is not necessarily fit to drive or to be served.
- The medical mimic: diabetes, head injury, stroke, heat illness, and drug use can look exactly like intoxication. Do not diagnose and do not serve; stop service and get help.
- The single-cue trap: one cue is weak evidence; three or more cues across different categories is a strong, defensible basis for refusing service.
Worked rule of thumb: if you can point to at least three cues in at least two categories, stop alcohol service and switch to water, food, and a plan for getting the guest home.