The breathtaking truth about breath alcohol readings of zero

Introduction
It has been postulated that the hangover state starts when breath alcohol concentration is zero.
Methods
Data from 2 studies that assessed ethanol in breath, blood and urine were compared.
Results
The data revealed that ethanol may still be present in the blood and urine during the hangover state, despite breath analyser readings of zero.
Discussion
As ethanol is still present in the body despite zero breath alcohol readings, the current consensus to postpone cognitive testing in hangover studies until breath alcohol concentration is zero should be reconsidered.