metabolic acidosis, disturbed prostaglandin synthesis, increased cardiac output, vasodilation, sleep deprivation and insufficient eating. Some complex organic molecules found in alcoholic beverages known as congeners may play an important role in producing hangover effects because some, such as methanol, are metabolized to the notably toxic substances formaldehyde and formic acid. Pathophysiology After being ingested, the ethanol in alcoholic beverages is first converted to acetaldehyde by the enzyme alcohol dehydrogenase and then to acetic acid by oxidation and egestion process. These reactions also convert nicotinamide adenine dinucleotide (NAD+) to its reduced form NADH in a redox reaction. By causing an imbalance of the NAD+/NADH redox system, alcoholic beverages make normal bodily functions more difficult. Consequences of the alcohol induced redox changes in the human body include increased triglyceride production, increased amino acid catabolism, inhibition of the citric acid cycle, lactic acidosis, ketoacidosis, hyperuricemia, disturbance in cortisol and androgen metabolism and increased fibrogenesis. The metabolism of glucose and insulin are also influenced. However, recent studies showed no significant correlation between hangover severity and the concentrations of various hormones, electrolytes, free fatty acids, triglycerides, lactate, ketone bodies, cortisol, and glucose in blood and urine samples. Alcohol also induces the CYP2E1 enzyme, which metabolizes ethanol and other substances into more reactive toxins. In particular, in binge drinking the enzyme is activated and plays a role in creating a harmful condition known as oxidative stress which can lead to cell death. Acetaldehyde Acetaldehyde, the first by-product of ethanol, is between 10 and 30 times more toxic than alcohol itself and can remain at an elevated plateau for many hours after initial ethanol consumption. In addition, certain genetic factors can amplify the negative effects of acetaldehyde. For example, some people (predominantly East Asians) have a mutation in their alcohol dehydrogenase gene that makes this enzyme unusually fast at converting ethanol to acetaldehyde. In addition, about half of all East Asians convert acetaldehyde to acetic acid more slowly (via acetaldehyde dehydrogenase), causing a higher buildup of acetaldehyde than normally seen in other groups. The high concentration of acetaldehyde causes the alcohol flush reaction, colloquially known as the "Asian Flush". Since the alcohol flush reaction is highly uncomfortable and the possibility of hangovers is immediate and severe, people with this gene variant are less likely to become alcoholics. Acetaldehyde may also influence glutathione peroxidase, a key antioxidant enzyme, and increases the susceptibility to oxidative stress. Likewise, acetic acid