Final answer:
The primary contributors to hangover symptoms from alcohol consumption are acetaldehyde, the product of ethanol metabolism, and methanol, which produces toxic methanal upon metabolism.
Step-by-step explanation:
The compounds in alcohol that may contribute to hangover symptoms primarily include ethanol, which can lead to the production of acetaldehyde during metabolism. This substance is responsible for many of the unpleasant effects of drinking too much alcohol, such as flushing, nausea, dizziness, sweating, headache, and low blood pressure. Acetaldehyde is normally further metabolized to harmless acetic acid, but when the enzyme (aldehyde dehydrogenase) that performs this function is inhibited, as is the case with Antabuse drugs, these effects are exacerbated. Additionally, impurities or congeners in certain alcoholic beverages may contribute to hangover symptoms.
Another hazardous compound is methanol, which can be found in trace amounts in alcoholic beverages. Methanol is metabolized to methanal (formaldehyde), a toxic substance that damages tissues and can cause blindness. To treat methanol poisoning, ethanol is administered to compete with methanol for the enzyme that metabolizes both compounds, therefore preventing the formation of the poisonous methanal and allowing the methanol to be excreted by the body.