How is alcohol absorbed and metabolized?

Alcohol, specifically ethanol, is primarily absorbed and metabolized in the liver. The process involves several steps:

1. Absorption:

- Alcohol consumption occurs mostly through oral ingestion.

- Once ingested, alcohol is absorbed into the bloodstream mainly through the stomach and small intestine.

- The rate of absorption depends on various factors, including the amount consumed, food intake, and individual differences in absorption rates.

2. Metabolism:

- The liver is responsible for metabolizing the majority of alcohol consumed.

- Alcohol metabolism involves several enzymes, primarily alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH).

- ADH initially converts alcohol into acetaldehyde, which is a toxic compound.

- Acetaldehyde is further metabolized by ALDH into acetate (acetic acid), a less harmful substance that can be used as energy or eliminated from the body.

3. First-Pass Metabolism:

- A portion of the alcohol consumed is metabolized before it enters the systemic circulation.

- This occurs during the "first-pass" metabolism in the liver.

- First-pass metabolism reduces the amount of alcohol that reaches the rest of the body.

4. Elimination:

- Once metabolized, alcohol primarily leaves the body through urine, breath, and sweat.

- The rate of elimination varies depending on factors like age, sex, and overall health.

5. Hangover:

- The unpleasant symptoms experienced after excessive alcohol consumption are collectively known as a hangover.

- The exact mechanisms of hangovers are not fully understood, but factors such as dehydration, inflammation, and imbalances in neurotransmitters are believed to contribute to these symptoms.