It all seemed to be going so well the night before. The music was pumping, your heart was light, and you were making new friends as you partied the night away with old ones. However, as the festivities wore on and the dead soldiers piled up, you and your friends got buzzed, then sailed right past tipsy, and before the night was out, you had consumed enough alcohol to have you on your knees, praying to the porcelain goddess for relief and wondering, “How did I get myself into this?” The sad thing is, your troubles were just beginning. When you woke up the next morning you would be wallowing in the agony of that timeless enemy of all drinkers: the hangover.

Does this sound familiar? Almost anyone who has had a bit too much to drink before knows how the ecstasy of night of carousing becomes the debilitating malaise of the next morning’s hangover. The suite of symptoms that may accompany this common affliction include:

• Headache
• Body Ache
• Dry mouth
• Fatigue
• Brain fog
• Nausea
• Diarrhea or Acid Reflux
• Depression, anxiety, irritability
• Increased heart rate

If you are wondering how something that makes you feel so good can suddenly turn on you and make you feel so bad, you are not alone. It turns out a hangover is a complex set of physiological processes that science has yet to fully understand. In this article we will look at some of the more prominent ways alcohol can screw with your body and make you wish you were never born. These include effects on your:

• Fluid Homeostasis
• Endocrine system
• Liver
• Immune system 
• Digestive system

Alcohol Dehydrates You

The first and most well known cause of a hangover is dehydration. Alcohol dehydrates you because it functions as a diuretic (makes you urinate). It does this because it interferes with the release of vasopressin, a hormone that regulates your fluid homeostasis. Basically, vasopressin stops you from peeing all the time and when alcohol knocks out your vasopressin production, you do just that. Alcohol will stimulate you to lose fluid at a ratio of about 4:1. If you drink a cup of alcohol, you will pee out four cups of water. 

All this fluid release dehydrates you, draining you of electrolytes and bringing on all the classic symptoms of dehydration like:

• Dizziness
• Fatigue
• Dry mouth/ Strong thirst 
• Confusion

As an interesting added benefit, this dehydration actually causes the brain to shrink. This shrinkage pulls on the meninges, which are the membranes that line the inner surface of the skull and causes the splitting headache hard drinkers know so well.

Alcohol Messes with your Endocrine System

Besides the hormone vasopressin, mentioned above, alcohol affects several other hormones as well.

The Renin-Angiotensin-Aldosterone System

The Renin-Angiotensin-Aldosterone System (RAAS) is a complex system of hormones that regulates the fluid and electrolyte balance in the body as well as controlling blood pressure. Alcohol stimulates the production of renin and aldosterone. This further exacerbates the dehydration issue mentioned above and may be responsible for some of the increased heart rate some people get with a hangover. 

There is even some interesting evidence that heightened aldosterone levels in people who drink often may contribute to the development of alcoholism. 

Glutamine Rebound

Glutamine is an amino acid that the body uses in a myriad of ways, including as a natural stimulant. Alcohol suppresses glutamine levels as long as you are drinking. When you finally get some sleep and your body processes the alcohol, the muscles go into overdrive, pumping out glutamine and creating a “rebound” effect. This interferes with the quality of your sleep and makes you feel like you haven’t slept at all. Glutamine rebound can also cause restlessness, sadness, and anxiety. 

Alcohol Overwhelms Your Liver

Acetaldehyde

90% of the work of breaking down alcohol is done by the liver. The liver metabolizes ethanol (they type of alcohol you drink) in a two-step process. First, an enzyme called alcohol dehydrogenase breaks the ethanol down into a substance called acetaldehyde. This is only meant to be an intermediary step, referred to as a secondary metabolite. 

Acetaldehyde is really nasty stuff. It is said to be 20-30 times more toxic than ethanol itself. Ideally, though, it doesn’t stick around for long. Your liver immediately releases the enzyme acetaldehyde dehydrogenase and an antioxidant called glutathione. Together, the two substances bind up this poison, whisk it away through your urine, and high-five each other on a job well done. 

Unfortunately, your liver only keeps a finite supply of glutathione on hand. When available stores of glutathione are used up,the liver has to rush to make more. In the meantime, the acetaldehyde builds up and roams free in the body, causing all kinds of mischief and making you feel really sick. That’s why this phenomenon only shows up when you drink a lot of alcohol. 

 An interesting side note is that Antabuse, a drug used to treat alcoholism, amplifies the consequences of drinking by interfering with your body’s breakdown of acetaldehyde. If you take antabuse and stay away from alcohol, you don’t feel a thing. However, if you drink alcohol at any time you are on Antabuse, you can’t break down acetaldehyde at all. Then the acetaldehyde runs rampant through your system and you probably feel sicker than you have ever felt in your life.

Methanol

Methanol is a close relative of ethanol. Also known as “methylated spirit” and “wood alcohol” methanol is very toxic beyond the trace amounts that occur naturally in fruits. 10 ml of methanol is enough to make you go blind and 30ml will kill you. Some of the darker colored alcoholic beverages like red wine and bourbon contain small amounts of methanol as an incidental byproduct. 

When you drink beverages that contain methanol, you don’t feel any ill effect right away. That’s because, just like ethanol, methanol gets broken down in a two step process. First, alcohol dehydrogenase (the same enzyme mentioned before), breaks the methanol down into its own secondary metabolite; formaldehyde.

That’s right folks. Embalming fluid. The stuff they use to pickle animal specimens or preserve a body for a funeral. Is it any wonder a hangover makes you feel so crummy when you have a few drops of embalming fluid coursing through your veins? 

Of course, your body doesn’t process the methanol right away. That’s the beauty of the hangover. Alcohol dehydrogenase has a stronger affinity for ethanol, so it processes that first. Only after all the ethanol has worked its way out of your bloodstream does your body begin to break down methanol. The methanol you drink in your Cabernet Sauvignon just floats around harmlessly in your system until a few hours after you go to sleep. Then your liver attacks the methanol and starts churning out formaldehyde. No wonder you feel like you’re being pickled from the inside out. 

Blood Sugar

While your liver is busy breaking down alcohol, it isn’t doing another essential job, which is producing glucose. As a result, your blood glucose levels drop and you are forced to break down glycogen stored in other parts of the body. This leads you to feel weak, lethargic,and depressed. 

Alcohol Causes an Immune Response

New research points to a previously unknown pathway by which alcohol makes you feel like crap: your immune system. Consumption of alcohol has been linked with the release of cytokines that can trigger a systemic inflammatory response. 

Alcohol Irritates Your Digestive System

Last but not least, alcohol damages the lining of your stomach. That stimulates the release of more stomach acid and can cause vomiting. Alcohol also seems to make the lining of the intestines more permeable, which causes it to leak undigested molecules into the bloodstream. This is a probable cause of the immune response mentioned above. 

After taking in all the diverse ways that we end up paying for a night of hard drinking, it’s amazing we survive it at all. The internet is full of supposed cures for hangovers, but the mechanisms of action in a hangover are so diverse, so strong, and so complex, that none of them are going to be a silver bullet. The best way of avoiding a hangover is common sense: take it easy on the booze in the first place!   

Do Hangover Cures Actually Work

Every drinker knows of a few hangover cures, ranging from Ibuprofen to certain vitamins (such as B and Zinc), and even “hair of the dog” (drinking more alcohol). While a good meal may help, the one solution you can rely on to help you feel better is lots of fresh, clean water. Even though some studies have shown that dehydration isn’t the biggest contributing factor to hangovers, health experts recommend drinking plenty of water anyway. Water is life. It helps our liver and kidneys function properly, which is how our bodies filter out contaminants. Even if you aren’t recovering from a bender, it’s always a good idea to stay hydrated.

The only sure-fire way to avoid a hangover is to drink less alcohol. While sobriety isn’t for everyone, even just commiting to a glass of water between drinks can make a big difference in how you feel the next morning. That may be partially due to the healthy effects of water, but mostly its because this strategy results in less alcohol consumption in the first place.