The Science Behind Alcohol & Hangovers

By: Sophia Erickson

Anyone who’s ever shamelessly polished off one too many glasses of wine, mixed drinks, beers, shots, or all of the above, is familiar with the gut wrenching malady and deep sense of regret that so kindly ensue after a night of drinking. But what is alcohol doing to our bodies that induces such a disgusting feeling and why is there no cure for a hangover? Lucky for you, I have some answers to these questions, and tips on how to bounce back after a big night out (or shall we say big night in thanks to COVID).

What does alcohol do to our bodies and brains? 

When you drink, your body doesn’t actually digest the alcohol. It is absorbed through the lining of your stomach into your bloodstream, which then diffuses it into biological tissues throughout your body (Paton, 2005). Alcohol reaches your brain in only five minutes, with immediate effects appearing within 10 minutes. 

The immediate effects of alcohol on the brain are due to its influence on the organ’s communication and information-processing pathways. The sense of euphoria that is first experienced when drinking is due to the release of dopamine, which creates a pleasurable sensation in the body (Di Chiara, 1997). This allows you to feel relaxed, but may also cause minor impairment of reasoning and memory. Once your body tissues begin to absorb extra alcohol, your blood alcohol content (BAC) rises and important brain regions begin malfunctioning. 

Alcohol impairs the occipital, temporal and frontal lobes, which can lead to sensations of blurred vision, slurred speech and lack of control, respectively (Oscar-Berman, 2007). The parietal lobe, which processes sensory information, is also affected, resulting in loss of fine motor skill and slower reaction times (Oscar-Berman, 2007). If alcohol is consumed rapidly and BAC levels continue to rise, the cerebellum, which is responsible for coordination, is impacted, resulting in impaired walking/standing (Oscar-Berman, 2007). Finally, if BAC levels get too high it can even impact the hippocampus, which is responsible for making new memories (White, 2003). This is why after a big night of drinking some people cannot remember everything that happened. 

While there is typically a universal effect of lowered inhibition, remember that the degree of intoxication- and its effect on the brain/body- depends on many other factors such as age, gender, weight, type of alcohol consumed, food consumption before, during and after drinking, and rate of metabolization. 

How do our bodies metabolize alcohol?

Our bodies metabolize alcohol using the enzyme alcohol dehydrogenase (ADH) (Cederbaum, 2012). As ADH breaks down ethanol ,the intoxicating ingredient in alcoholic beverages, it forms acetaldehyde which is registered as both a poison and a carcinogen in the body (Seitz, 2010). After this, the acetaldehyde turns into acetate and then finally into carbon dioxide and water. 

Some people have genetic variants of the enzymes that make this breakdown more or less efficient, however, no matter how much alcohol you consume, your body can only metabolize a certain amount every hour. According to a study done by the Virginia Alcoholic Beverage Control Authority, “If a 120-pound woman has four standard size drinks, which equal a BAC of approximately .15 percent, it will take approximately nine and a half hours for her BAC level to return to zero.” Other factors affecting how fast alcohol is metabolized includes age, weight, gender, medications, health conditions and time between consumption of each beverage. 

What is a hangover?

A hangover is defined as a group of unpleasant signs and symptoms such as fatigue, headache, vomiting, sensitivity to light, dizziness and mood changes, that can develop after drinking too much alcohol (Swift, 1998). While researchers are still unsure of every reason that our bodies experience hangovers, it is simply our bodies biochemical and neurochemical reaction to alcohol.

Why does it make me feel sick? 

  1. Alcohol dehydrates the body. Once alcohol reaches your bloodstream, it suppresses vasopressin production, which exacerbates the diuretic effect and leads to dehydration(Polhuis, 2017). This leads to the thirst, weakness, dizziness, and lightheadedness you may experience.
  2. Excessive alcohol intake can cause stomach inflammation. Alcohol can also produce fatty liver, gastric acid, and pancreatic and intestinal secretions, all of which can cause abdominal pain, nausea, and vomiting (Bishehsari, 2017).
  3. Alcohol lowers your blood sugar levels. Alcohol consumption can inhibit glucose production in the body and deplete the reserves of glucose stored in the liver (Steiner, 2015). Because glucose is the main energy source of the brain, low blood sugar can produce symptoms of fatigue, weakness and mood disturbances experienced during hangovers.
  4. Alcohol can disrupt your sleep cycle. Typically, alcohol disrupts your body’s temperature and hormone release which leads to shorter and poorer quality sleep that can cause fatigue or that “jet lagged” feeling the day after drinking (Stein, 2005).
  5. Alcohol causes headaches. Intoxication can result in the widening of blood vessels (vasodilatation), which can lead to a headache.  Alcohol consumption also affects histamine, serotonin, and prostaglandins, hormones thought to contribute to headaches (Panconesi, 2016). 
  6. Alcoholic beverages contain congeners, or chemical compounds that contribute to the taste, smell, and appearance of the beverage (Rohsenow, 2010). These congeners, which include the toxin acetaldehyde, linger in the body long after your BAC has returned to normal. Remember, your brain and body register these chemicals as poison, so it makes sense why your body has such an adverse reaction.  

All this being said, everything is ok in moderation. Just because you drink alcohol (21+ of course), doesn’t mean you have to wait up feeling sick the next day. There is still no magic cure for the intense feelings of a hangover but there are definitely some things you can do to help you drink responsibly and make your Sunday scaries  a little less  ~ scary ~.

  1. Drink less. It seems pretty self explanatory, but you would be surprised at how many people don’t realize that. Also, don’t give into peer pressure. You know your own limits, so why would you let other people set them for you?
  2. Pace yourself and remember that drinking can be leisurely and fun. Try alternating between a mocktail or seltzer after every alcoholic drink.
  3. Hydrate and don’t drink on an empty stomach. Again, these seem pretty self explanatory, but lack of food and water can accelerate intoxication quickly. Before drinking, eat lots of healthy proteins, fats and carbs and before you go to bed, try to drink at least one full glass of water.
  4. Try clear spirits. Research has shown beverages that are basically pure alcohol, such as gin or vodka, cause fewer hangover effects. Beverages that contain more congeners such as whiskey, brandy, and red wine tend to cause more hangover symptoms.

Reference List:

Bishehsari, F., Magno, E., Swanson, G., Desai, V., Voigt, R. M., Forsyth, C. B., & Keshavarzian, A. (2017). Alcohol and Gut-Derived Inflammation. Alcohol research : current reviews, 38(2), 163–171.

Cederbaum A. I. (2012). Alcohol metabolism. Clinics in liver disease, 16(4), 667–685.

Di Chiara G. (1997). Alcohol and dopamine. Alcohol health and research world, 21(2), 108–114.

n.a. (n.d.). Alcohol Education Basics Guide. Virginia ABC Education and Prevention Toolkit Series. Retrieved from

Oscar-Berman, M., & Marinković, K. (2007). Alcohol: effects on neurobehavioral functions and the brain. Neuropsychology review, 17(3), 239–257.

Panconesi A. (2016). Alcohol-induced headaches: Evidence for a central mechanism?. Journal of neurosciences in rural practice, 7(2), 269–275.

Paton A. (2005). Alcohol in the body. BMJ (Clinical research ed.), 330(7482), 85–87.

Polhuis, K., Wijnen, A., Sierksma, A., Calame, W., & Tieland, M. (2017). The Diuretic Action of Weak and Strong Alcoholic Beverages in Elderly Men: A Randomized Diet-Controlled Crossover Trial. Nutrients, 9(7), 660.

Rohsenow, D. J., & Howland, J. (2010). The role of beverage congeners in hangover and other residual effects of alcohol intoxication: a review. Current drug abuse reviews, 3(2), 76–79.

Seitz, H. K., & Stickel, F. (2010). Acetaldehyde as an underestimated risk factor for cancer development: role of genetics in ethanol metabolism. Genes & nutrition, 5(2), 121–128.

Stein, M. D., & Friedmann, P. D. (2005). Disturbed sleep and its relationship to alcohol use. Substance abuse, 26(1), 1–13.

Steiner, J. L., Crowell, K. T., & Lang, C. H. (2015). Impact of Alcohol on Glycemic Control and Insulin Action. Biomolecules, 5(4), 2223–2246.

Swift, R., & Davidson, D. (1998). Alcohol hangover: mechanisms and mediators. Alcohol health and research world, 22(1), 54–60.

White A. M. (2003). What happened? Alcohol, memory blackouts, and the brain. Alcohol research & health : the journal of the National Institute on Alcohol Abuse and Alcoholism, 27(2), 186–196.

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