Having a glass of Pinot Noir with dinner can seem like no biggie, but sometimes a hangover is your reward for your moderation anyway. Just one glass of wine can affect your body in a bunch of ways in the 24 hours after you drink it, from your sleep to your heart rate.
"Once you drink a glass, alcohol is quickly absorbed into the blood and moves throughout your body," Dr. Neha Pathak M.D., medical editor of WebMD, tells Bustle. "A small amount is absorbed into small blood vessels in your mouth, but most is absorbed into the bloodstream from your stomach and small intestine." Around 20% dissipates in the stomach, according to Addiction Center, a referral service for substance use disorder treatment, while the remainder is digested in the small intestine. The liver breaks down the alcohol at a rate of about one drink per hour, which means that by the time you wake up the next morning, your one drink will be thoroughly processed.
But not everybody processes alcohol in the same way, or at the same speed. The effects of alcohol after a 24-hour period, Dr. Pathak says, depend on how quickly your body can break down alcohol, whether you drank it on an empty stomach, how quickly you drank it, and your tolerance. If you have wine once in a blue moon, chances are you'll feel the effects faster and with more intensity than somebody who has Chardonnay after work a few times a week. And having food, particularly fatty food, in your stomach will delay how quickly your drink is broken down.
The type of wine you choose may affect your reactions, too. If you're very sensitive to the histamines in red wine — red can have up to 200% more histamines than white — then you might end up having a headache in about 15 minutes, even after one drink. Noticing that you reach for the Advil after a single glass of Merlot? It could be time to talk to your doctor about an allergy test.
Red wines have advantages, though. "The polyphenols in red wine trigger the release of nitric oxide, which could relax your stomach and help with digestion," OneMedical provider Dr. Natasha Bhuyan, M.D., tells Bustle.
You might feel some increased heart rate and blood pressure changes, but science says they'll disappear pretty quickly. "For small amounts of alcohol, it probably wouldn't cause any drastic changes the next day, but some studies have shown a mild increase in blood pressure the next morning," Dr. Pathak says. A study published in Alcohol Research: Current Reviews in 2020 discovered that one to two standard drinks were associated with small blood pressure increases that faded over time. But another review of 32 studies published in Cochrane in 2020 found that, after six hours, a single dose of alcohol tended to increase heart rate but didn't do much for blood pressure. Whatever that glass of wine does, it seems it won't last very long.
"A single glass of wine could also be dehydrating if you are not well hydrated before drinking the wine," Dr. Bhuyan tells Bustle. You might feel a little fuzzy and more likely to giggle and forget trivia questions, but that won't last either. "Changes to thinking, coordination and memory likely will resolve by the next day," Dr. Pathak says.
The one area where one glass of wine might really dent your day-after buzz is your sleep. "Alcohol can cause sleep disturbance, so you may be more fatigued or tired the next day," Dr. Pathak says. One glass of wine, it seems, won't affect very much when you wake up the morning after — but if you get headaches, toss and turn all night, or just don't feel like yourself, it could be a good idea to chat to a doctor.
Dr. Natasha Bhuyan M.D.
Dr. Neha Pathak M.D.
Piano, M. R., Thur, L. A., Hwang, C. L., & Phillips, S. A. (2020). Effects of Alcohol on the Cardiovascular System in Women. Alcohol research : current reviews, 40(2), 12. https://doi.org/10.35946/arcr.v40.2.12
Tasnim, S., Tang, C., Musini, V.M., Wright, J.M. (2020) Effect of alcohol on blood pressure. Cochrane Database of Systematic Reviews, Issue 7. Art. No.: CD012787. DOI: 10.1002/14651858.CD012787.pub2.