The Science Of A Hangover
Published December 2018
What It Means for Recovery Mode
Still reeling from last night’s generous pour of bubbly?
For as common as they are, there is still much to be understood about hangovers. The long-term impact of alcohol is well-understood, but the mechanisms that occur during a hangover are a bit cloudier. Here’s what we know.
What’s Really Going On When You Drink?
When you consume alcohol, it becomes absorbed into your bloodstream until the liver can break it down. Once in the bloodstream, it only takes roughly five minutes to reach your brain, and effects peak after 30 to 90 minutes.
Drinking too much alcohol can lead to dangerous impairment, sometimes called acute alcohol exposure. “There is a blood brain barrier, which acts as a gateway for substances like proteins and nutrients to get into the brain. Alcohol crosses this barrier very quickly, which is why acute alcohol exposure happens,” says Northwestern Medicine Neurologist Kapil Sachdeva, MD.
Meanwhile, your liver works to break down the alcohol using enzymes. While your liver accounts for metabolizing roughly 90 percent of alcohol, small amounts may also be excreted through sweat, urine and your lungs — which explains how breathalyzer tests detect alcohol.
Alcohol also impacts the kidneys, which are responsible for removing waste and keeping you hydrated. When there is too much alcohol in the system — more than three drinks in a day for women and four for men — the kidneys can no longer function properly. “Alcohol is a diuretic, so it makes you dehydrated, and may cause dizziness or generalized weakness,” Dr. Sachdeva continues.
As you can see, your entire body must work to process and eliminate alcohol. This means various factors may be responsible for your hangover and lead to certain symptoms, including:
- Dehydration. Your kidneys produce more urine, which can led to dehydration and an imbalance of electrolytes. This results in thirst, dry mouth, a headache and nausea.
- Gastrointestinal disturbances. Alcohol may irritate the stomach, which can cause inflammation. You may also experience an increase in stomach acid, which can cause abdominal pain or nausea. When you are metabolizing alcohol, your liver releases a byproduct known as acetaldehyde, which may result in nausea or vomiting.
- Lowered blood sugar. If your blood sugar drops, you may feel weak or tired. This is especially important for those who have diabetes, as it can become dangerously low.
- Disruption of sleep. Alcohol prevents deep stages of sleep, which is necessary for letting your body restore itself.
How to Recover
First things first: ‘Hair of the dog’ is not recommended. Not only is there no concrete evidence that more alcohol will help you feel better, it could also indicate a sign of dependency. “You’re only going to overwhelm your liver, which is already working overtime,” says Dr. Sachdeva.
The best approach to a hangover is to simply help your body recover. From Gatorade to Pedialyte, many people swear by electrolyte-filled drinks as the miraculous elixir to banish hangovers. These look to replenish nutrients more quickly than water, and can help with dehydration and electrolyte imbalance. They contain sodium and potassium, substances that do a better job keeping you hydrated than just water, which is lost during urination.
Could a giant, greasy burger help curb your hangover? While food helps slow down the absorption of alcohol, it should be consumed before you start sipping. That said, if you’re feeling rough the next morning, bland foods or fruits can help raise your blood sugar as well as relieve nausea.
Certain medications may help ease symptoms, particularly headaches. However, acetaminophen (an alternative to aspirin) can cause liver damage.
“If someone found a cure for a hangover, they’d be very wealthy,” says Dr. Sachdeva. “People have looked at a lot of things to prevent a hangover or treat the symptoms, but nothing has really stood out.”
Long-Term Effects of Alcohol
Though a hangover generally lasts 24 hours, there are several lingering effects of alcohol.
Alcohol impacts the brain’s pathways, which can affect how the brain works. “Repeated alcohol use can lead to neuropathy, which is damage to the peripheral nerves, causing numbness and pain in feet and hands.” says Dr. Sachdeva. “You’ll start to notice problems with imbalance and poor coordination. We do see cognitive side effects or accelerated brain atrophy.” Though rare, chronic alcohol use can lead to serious disorders such as Wernicke syndrome, which can occur when there is a significant thiamin deficiency due to alcoholism.
Your liver’s significant role in breaking down waste comes at a cost. Over time, alcohol abuse can cause lasting damage. A build-up of fat or prolonged inflammation can result in alcohol-induced liver disease, including fatty liver, alcohol hepatitis and cirrhosis. The build-up of fats in the blood can also be taxing on your heart, which increases blood pressure.
The True Cure?
Though hangovers will eventually go away by themselves, the best approach is to avoid them entirely by simply drinking in moderation. “One may wonder whether a remedy is needed at all,” says Dr. Sachdeva. “It’s your body’s way of saying you shouldn’t be drinking that much and without that signal, it could lead to problems down the road, such as paving the way to addiction.”
Next time, alternate with water and consider one fewer round.