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What Causes Hangovers?

What Causes Hangovers

After a night of heavy drinking most of us wake up the next morning feeling utterly horrible. We feel horrible for many different reasons. Symptoms associated with a hangover include all of the following:

  • Nausea/Vomiting
  • Intense Headaches
  • Sensitivity to Light and Sound
  • Anxiety / Restlessness
  • Feeling Down or Depressed
  • Brain Fog
  • Fatigue and Feelings of Weakness
  • Dry Mouth

There are many biological processes which contribute to a hangover. Some of these influence the severity of a hangover more than others. Furthermore, different processes contribute to different hangover symptoms. There is no single process which causes every hangover symptom.

If you were to ask someone “What causes a hangover?”, chances are you would get different answers from different people. The most common answer you would hear is “Dehydration”. But the notion that dehydration is the main cause of a hangover is completely false. Dehydration only contributes to a couple of the symptoms listed above.

For those looking to prevent and cure hangovers, it is important to understand all the underlying factors and which hangover symptoms those factors influence. Some factors may also affect hangover severity more or less depending on the person’s biological habits and day to day habits. The purpose of this article is to list:

  • All the biological processes which contribute to hangover symptoms.
  • Exactly what is happening in your body as a result of each biological process.
  • Which specific hangover symptoms each cause exacerbates.
  • How severely each process exacerbates each symptom.
  • If there are any habits or factors which put you at risk for each cause.
  • How to lower hangover symptoms related to each cause.

Cause 1: Acetaldehyde Build-Up

Hangover Symptoms Caused by Acetaldehyde Build-Up

  • Headache
  • Vomiting / Nausea
  • Sensitivity to Light and Sound

After you consume alcohol it is metabolized by your liver. You liver metabolizes alcohol into a substance called acetaldehyde. Eventually, the acetaldehyde is metabolized into acetic acid and then into carbon dioxide/water at which point it is completely expelled through your breath and urine.

Research shows that acetaldehyde is up to 30 times more toxic than alcohol. [1] Many scientists believe acetaldehyde is the main cause of hangovers. Symptoms associated with acetaldehyde poisoning include nausea, vomiting, headaches, and sensitivity to light.

For those who have had a hangover which made the sunlight blinding, acetaldehyde poisoning is the cause. Not only did it cause the sensitivity to light, but it greatly contributed to any headache or nausea felt that morning.

Evidence of how poisonous acetaldehyde is can be seen by examine a drug called Antabuse (Disulfiram). Antabuse was designed to treat alcoholism. It prevents your liver from breaking down acetaldehyde. Those who took Antabuse had levels of acetaldehyde 5-10 times higher than those who didn’t after consuming the exact same amount of alcohol. However, those who took the Antabuse quickly experienced crippling headaches, mental confusion, nausea, vomiting, and flushing of the skin.

How severely does acetaldehyde poisoning contribute to hangover symptoms?

If a main cause of hangovers were to be named, it would be acetaldehyde. This toxin greatly contributes to headaches, nausea, brain fog, and is the only cause of light sensitivity. It you experience light sensitivity along with an intense headache and extreme nausea, acetaldehyde is definitely at fault.

How can I lower hangover symptoms related to Acetaldehyde build-up?

In order to prevent hangover symptoms related to acetaldehyde build-up you have to flush the acetaldehyde out of your system as quickly as possible. One way to do this is by enhancing the enzyme responsible for breaking down acetaldehyde in your liver. This enzyme is called acetaldehyde dehydrogenase (ALDH).

One supplement known to enhance ALDH activity is Dihydromyricetin (DHM). Research shows DHM is able to not only promote ALDH activity but also ADH activity. [2] This unique benefit allows DHM to help your body metabolize not only acetaldehyde by also alcohol itself.

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Cause 2: Gastritis

Hangover Symptoms Caused by Gastritis

  • Nausea / Vomiting
  • Excessive Belching
  • Loss of Appetite
  • Feeling Bloated

Gastritis is defined as the inflammation of stomach lining. It is most commonly caused by alcohol consumption. Consuming even small amount of alcohol causes your stomach to produce excess amounts of stomach acid (hydrochloric acid). Having too much stomach acid irritates and inflames your stomach. This leads to nausea, vomiting, diarrhea, and bloody stools.

Gastritis will also cause vomiting at night if too much alcohol is consumed. If levels of hydrochloric acid in your stomach rise too high, a message is sent to your brain telling it you are being poisoned. In order to defend from the poison, your body makes you vomit in an attempt to flush itself of the toxins in your stomach.

How severely does gastritis contribute to hangover symptoms?

Behind acetaldehyde build-up, stomach inflammation/irritation is the leading cause of hangover nausea. Of course, this varies based on a person’s genetic make-up. Some people’s stomachs are more resilient than others, and may produce different amounts of stomach acid as a result of alcohol consumption. Hangover symptoms caused by stomach irritation may occur after only a small amount of drinks. For those who don’t experience hangover nausea, your stomach is likely somewhat resilient to the effects alcohol has on it.

How can I lower hangover symptoms related to Gastritis?

First and foremost, make sure you have eaten a large meal before you start drinking. The food will absorb alcohol and lessen the burden it places on your stomach.

Additionally, taking antacids such as Tums or Pepto Bismol can reduce the acidity of your stomach and lessen irritation/inflammation. These over-the-counter supplements are readily available online and at your local drug store.

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Cause 3: Dehydration

Hangover Symptoms Caused by Dehydration

  • Headaches
  • Thirst / Dry Mouth
  • Feeling Tired or Weak

Alcohol is a diuretic, meaning it causes your body to produce additional amounts of urine. Every time you drink a beer, you are technically hydrating yourself for a small amount of time. Beer is mostly water after all. However, alcohol causes you to produce levels of urine beyond what it would normally produce. This causes your body to lose not only water the beer provided you, but water previously consumed throughout the day.

Think of your body as a large tank of water. The more water in your tank, the more hydrated you are. Every time you drink a beer you pour 12 ounces of water into that tank. But shortly after you pour 12 ounces of water into it, you pour 14 ounces out. Drinking any type of alcohol provides your body with a net loss of water.

How much extra water does alcohol cause you to lose?

A single “drink” (12 oz 4.3% beer or 1.5oz 35% liquor) causes you to lose approximately 100ml of urine. To put this in terms which are easy to understand, 100ml converts to 3.3 ounces of liquid. In other words, by drinking just 3.5 beers you lose 12 ounces of urine, enough to fill a beer can.

Those who drink heavily for long periods of time, especially when not rehydrating themselves, can experience headaches, thirst, and fatigue as a result of dehydration. Having 10 alcoholic drinks in one night is enough to cause approximately two 16.9oz water bottles of extra urine production.

How Severely Does Dehydration Contribute to These Symptoms?

This depends almost entirely on how hydrated you are when you began to drink, and if you hydrated yourself throughout the night. If you drink 10 alcoholic beverages during a day and drink no water during that time, chances are you will experience a headache as a result of dehydration. Add in acetaldehyde build-up and the headache can be extremely brutal.

On the other hand, if you drink 10 alcoholic drinks throughout the night, are properly hydrated when you start drinking, and have 2-3 bottled waters while drinking, dehydration will not likely exacerbate or cause any hangover symptoms. The best way to determine if you are dehydrated is by how thirsty you, how dry your mouth is, and the color of your urine.

If you use the bathroom in the morning, excrete a low amount of urine, and your urine is dark yellow, you are dehydrated. This dehydration will likely exacerbate any hangover headaches one experiences.

How can I lower hangover symptoms related to Dehydration?

By ensuring you are properly hydrated before and during a night of drinking dehydration can easily be avoided. Simply drink 1-2 (16.9oz) bottles before you begin to drink and an additional bottle of water every 3 drinks. If you anticipate you will be hot or sweating, drink additional water.

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Cause 4: Loss of Electrolytes

Hangover Symptoms Caused by Loss of Electrolytes

  • Headache
  • Nausea / Vomiting

Electrolytes are various compounds which are used by your body to regulate many different functions. They are vital for your body’s ability to maintain homeostasis. They help regulate bodily fluid balance, neurological function, oxygen delivery, myocardial function, and acid-base balance. Your cells also use electrolytes to sustain electrical voltages between many cell membranes. Not having enough or having too many electrolytes can disrupt your body’s homeostasis and cause problems. Some commonly known electrolytes which are lost as a result of alcohol consumption include sodium, potassium, and calcium.

Alcohol causes you to lose electrolytes similar to the way it dehydrates you. Every time you urinate, your body loses electrolytes. Furthermore, you aren’t putting electrolytes in your body when you consume alcohol. All the urine you expel from drinking causes you to lose electrolytes, not just the extra urine.

The electrolytes you lose while drinking can’t be recuperated by drinking water alone. You must recuperate them by other means such as sports drinks like Gatorade or electrolyte supplements. This means even those who drink water throughout the night and stay properly hydrated may suffer an electrolyte imbalance from excessive drinking.

A mild to moderate electrolyte imbalance can cause headaches, nausea, and cramping. In fact, many endurance athletes who lose electrolytes through sweat take electrolyte supplements to prevent these symptoms.

How Severely Does Electrolyte Imbalance Contribute to These Symptoms?

This depends on a person’s genetics, what type of alcohol they are drinking, and how much alcohol is consumed in a night. People who drink large amounts of beer, wine, or mixed drinks as opposed to straight liquor are most at risk for suffering an electrolyte imbalance. Even though “extra” urine produced by all drinkers is the same, those who drink straight liquor consume less liquid and urinate less. Those who drink beer all night make more runs to the bathroom and expel more electrolytes.

Electrolytes are also lost through sweat. People drinking in the heat or dancing at clubs are at an increased risk for electrolyte loss and dehydration.

How can I lower hangover symptoms related to Loss of Electrolytes?

Simply make sure you are replenishing your electrolytes throughout the night while drinking. This can be done by drinking sports drinks such as Gatorade instead of water or by taking electrolyte supplements. When searching for a source of electrolytes, be sure it contains sodium, potassium, and calcium.

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Cause 5: Minor Alcohol Withdrawal

Hangover Symptoms Caused by Minor Alcohol Withdrawal

  • Poor sleep quality
  • Anxiety / Restlessness
  • Depression
  • Brain Fog

How Alcohol Affects the Brain

Within minutes of alcohol hitting your stomach it enters your blood stream and begins to affect your brain. Alcohol affects two different neurotransmitters in your brain; GABA and glutamate. Neurotransmitters are chemicals your brain cells use to send messages to each other. They heavily influence just not your emotions and thought processes, but also your movement and behavior.

In your brain, alcohol binds to your GABA receptors, and amplifies the message your brain cells receive from the GABA neurotransmitter. GABA is classified as an inhibitory neurotransmitter. Inhibitory neurotransmitters sedate you. As alcohol amplifies the message GABA is sending to your brain your heart rate slows, you feel relaxed, and your inhibitions are reduced. When alcohol is consumed to excess, GABA’s message is boosted to the point words begin to slur, motor control is impaired, and disorientation occurs. In extreme cases of alcohol overdose, breathing ceases completely, the heart stops, and coma or death occur.

Glutamine is the other neurotransmitter alcohol affects. Glutamine is an exhibitory neurotransmitter. When your brain receives a stronger message from Glutamine, brain activity, heart rate, and energy levels increase. Alcohol effects Glutamine opposite the way it affects GABA. Alcohol dampens the message your brain receives from Glutamine. This enhances alcohol’s sedative properties.

What Happens When You Stop Drinking?

When you stop drinking two things happen. First, your brain believes your GABA neurotransmitters are sending out stronger signals. This causes your brain to release less GABA and you get less of an effect from GABA than you normally would. Second, your brain believes Glutamine is sending out weaker signals. This causes it to kick into overdrive and produce more Glutamine than you actually need.

Not only does this disrupt sleep at night, but it can cause restlessness, feelings of depression, and anxiety. For those who find themselves waking up after only 5 or 6 hours of sleep unable to go back to bed, the rebound effect on GABA and Glutamine neurotransmitters is the cause.

How Severely Does Minor Alcohol Withdrawal Contribute to These Symptoms?

How severely minor alcohol withdrawal effects a person depends heavily on their genetic make-up, the amount they drank at night, and how often they drink. Generally, the only symptoms people experience from minor alcohol withdrawal is early awakenings and trouble falling back asleep and brain fog. For some people, anxiety and restlessness occur.

How can I lower hangover symptoms related to minor alcohol withdrawal?

In order to lessen hangover symptoms related to GABA and Glutamine rebound, you need to normalize your body’s level of these neurotransmitters as quickly as possible. This can be done by lessening alcohol’s effect on one or both of these neurotransmitters while drinking, or right after drinking.

One supplement which is able to counteract alcohol’s effect on GABA receptors is Dihydromyricetin(DHM). Research shows DHM is able to bind to GABA receptors and lessen the alcohol’s effect on GABA. [3] This provides DHM with the following benefits:

  • Reduce GABA rebound and counteract alcohol withdrawal symptoms
  • Reduce feelings of intoxication
  • Counteract alcohol dependence

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Cause 6: Reduction in Sleep Quality

Hangover Symptoms Caused/Exacerbated by Reduced Sleep Quality

  • Brain Fog / Trouble Thinking Clearly
  • Fatigue

A compilation of 25 different studies has shown that alcohol reduces sleep quality. [4] In other words, getting 8 hours of sleep after a night of drinking is less rejuvenating than getting 8 hours of sleep while sober.

When someone consumed alcohol before falling asleep, it reduces the amount of time spent in Rapid Eye Movement (REM) sleep. REM sleep is believed to be responsible for consolidating short term memories into long term memories. Being deprived of REM sleep at night has been linked to decreases in concentration, memory, and motor skills.

How severely does reduced sleep quality cause/exacerbate hangover symptoms?

A reduction in sleep quality isn’t going to be the main cause of the worst hangover symptoms out there. It won’t give you a headache or make you sick to your stomach. It will just leave you feeling groggy and tired.

If you are the type to experience early awakenings due to alcohol consumption followed by trouble sleeping the consequences are more severe. Even though your hangover symptoms won’t be amplified, it can take much longer to recover from them without a good night’s sleep. This can cause headaches and nausea to persist well into the day when 3 more hours of sleep would have been able to cure it much faster.

How can I lessen hangover symptoms caused by reduced sleep quality?

The best way is to simply sleep longer than normal. Make sure you can get 9 or 10 hours of sleep instead of 8. If you keep waking up, let yourself fall back asleep. The only way to cure a lack of sleep is to get more sleep.

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Summary of Hangover Symptoms and Causes

The following chart lists each symptom of a hangover and details the causes most responsible.

Hangover Symptoms

Dihydromyricetin can help address every cause of a hangover except for dehydration. Give it a try risk free and you'll never have to suffer from a hangover again.

Cited Studies


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