Wednesday, December 10, 2008
A hangover (veisalgia) describes the sum of unpleasant physiological effects following heavy consumption of drugs, particularly alcoholic beverages. The most commonly reported characteristics of a hangover include headache, nausea, sensitivity to light and noise, lethargy, dysphoria, and thirst.
Hypoglycemia, dehydration, acetaldehyde intoxication, and vitamin B12 deficiency are all theorized causes of hangover symptoms. Hangovers may last up to two or three days after alcohol was last consumed. Roughly 25-30% of drinkers may be resistant to hangover symptoms. Some aspects of a hangover are viewed as symptoms of acute ethanol withdrawal, similar to the longer-duration effects of withdrawal from alcoholism, as determined by studying the increases in brain reward thresholds in rats (the amount of current required to receive to electrodes implanted in the lateral hypothalamus) following ethanol injection.