A hangover is the cumulative effect of symptoms caused by a recent period of heavy drinking. Hangovers can occur at any time of day – they're not just a morning thing.
Typical symptoms associated with a hangover may include headache, dizziness, drowsiness, concentration problems, dry mouth, stuffy nose, fatigue, upset stomach, irritability, impaired judgment and increased sensitivity to bright light. In addition to the physical symptoms, the sufferer may also experience emotional symptoms; such as increased levels of anxiety and depression.
When flying, a hangover effect can be just as dangerous as alcohol intoxication. Even after your body finishes processing the alcohol in your system, a hangover may continue to impair your performance. The majority of effects associated with a hangover relate to the brain, the eyes, and the inner ear – all of which are vital when flying.
These undesirable effects can continue for up to 72 hours after your last drink.
Visual symptoms include eye muscle imbalance – which leads to double vision and difficulty focusing.
Inner ear effects include dizziness and decreased hearing perception.
If you are also suffering from other negative effects, such as sleep deprivation or fatigue, the hangover becomes magnified.