Does Alcohol Dehydrate You? 

Feeling groggy? Does it seem like no matter how much water you drink, you’re still thirsty? These are signs of dehydration. Does alcohol make you dehydrated? There are many things that can make you dehydrated, but alcohol is a notorious one! 

Let’s delve deeper into the science behind dehydration, how alcohol dehydrates us, and ways we can treat and avoid excessive dehydration from alcohol.

Dehydration Basics

Our body requires water and fluids to maintain normal functions. Dehydration is when we lose more fluids than we take in. Water and other fluids in our body are important for regulating body temperature, keeping our tissues (such as eyes, nose, and mouth) moist, protecting organs and tissues, carrying nutrients and oxygen to cells, and dissolving minerals and nutrients to make them accessible to our body. When we get dehydrated, our body is unable to regulate these important functions, putting us at risk of various health complications. 

We can become dehydrated from simply not drinking enough water. Whether we’re too busy and forget to drink water, have a lack of access to safe water, or we don’t have enough water while traveling, hiking, or camping, there are many reasons we might not be getting enough H2O throughout our day. However, these are not the only reasons our body loses fluids. Let’s look at some other ways we may lose electrolytes or fluids from our body:

• Fever. When we have a fever, our body tries to lower our temperature by losing fluids through our skin. Sometimes the fever causes us to sweat, and if we aren’t feeling well we might not drink enough water to replenish those lost fluids. 
• Excessive sweating. When we sweat, we lose fluids and electrolytes from our skin to help us cool off. Doing hot yoga, playing soccer on a hot day, or even basking outside in hot, humid weather can lead to us sweating out more fluids than we take in. 
• Urination. Urination is a way our body releases toxins. Some health conditions can increase our urine output and how many times a day we go. This excessive urination contributes to dehydration. 
• Diarrhea and vomiting. Illnesses or conditions that cause diarrhea or vomiting can result in dehydration. Diarrhea and vomiting result in too much water being expelled from our body, resulting in loss of fluids and electrolytes. 

No matter the cause of our dehydration, it’s important for us to replenish our fluids as soon as possible. Being dehydrated can lead to some serious consequences, which we’ll investigate further.

Health Risks From Dehydration

When our body lacks fluids, it can lead to many health risks. First, let’s take a look at some basic signs and symptoms of dehydration. 

• Headache
• Lightheadedness or dizziness
• Decreased urination
• Dark yellow or amber colored urine
• Dry mouth or dryness in other mucous membranes (lips, gums, nostrils) 
• Decreased skin elasticity
• Extreme thirst 
• Tiredness 

If we notice these symptoms, we should increase our fluid intake. But what happens if our dehydration goes untreated for a long period of time? Well, it can get pretty serious. Let’s take a look at some health consequences caused by severe dehydration: 

• Heat injury. If we don’t have enough fluids in our body, we will not be able to sweat properly. Sweating allows us to maintain a healthy body temperature, so when our perspiration is lacking, it can lead to heat-related illnesses such as heat cramps, heat exhaustion, or heat stroke. 
• Swelling of the brain. Swelling in the brain is referred to as cerebral edema. Edemas occur when there is too much fluid trapped in the body’s tissue, and a cerebral edema is when fluid builds up in our brain tissue. A cerebral edema can occur as a side effect of not rehydrating carefully after being dehydrated, and the body may pull too much fluid back into our brain cells at once. 
• Seizures. Electrolytes are minerals in our body that carry an electrical charge. Electrolytes are important for cell-to-cell communication, especially in our brain. When we get dehydrated, our electrolytes become imbalanced, and the normal electrical messages can become mixed up and lead to seizures. 
• Kidney failure. Dehydration can lead to a buildup of wastes and toxins in the body. The kidneys remove toxins from our body, but if we’re dehydrated for a long period of time, these toxins can build up and clog the kidneys. 
• Coma and death. Severe dehydration is fatal if left untreated, as our body needs fluids to maintain all its bodily functions. As the body becomes more severely dehydrated, the kidneys begin to shut down, eventually affecting other organs including the brain, which can lead to a coma in severe cases.

Severe and lasting dehydration is extremely dangerous and usually requires medical treatment, whereas most cases of mild or moderate dehydration can be resolved by drinking more fluids. But what about alcohol dehydration?

Alcohol and Dehydration

Alcohol can lead to dehydration, but why does alcohol dehydrate you? There are several ways alcohol can dehydrate us. When we drink alcohol, it gets absorbed into our bloodstream through our stomach but mostly through our small intestines. From there, the alcohol is processed by enzymes in the liver. As the liver breaks down the alcohol, it is converted into a substance called acetaldehyde, which can be toxic in high doses. Our liver quickly works to break down acetaldehyde into acetate. According to science, about 90% of alcohol is eliminated by our liver, but 2-5% of alcohol leaves our body through urine, sweat, or breath. And since alcohol increases our heart rate, it makes us sweat more, which accelerates how fast we become dehydrated.

Since alcohol travels through the bloodstream, it can travel to other areas of our body including the pituitary gland in our brain. The pituitary gland is responsible for regulating our growth, metabolism, and reproduction by creating and regulating hormones. When alcohol reaches the pituitary gland, it blocks the creation of vasopressin, which is known as the antidiuretic hormone or the hormone that helps us retain fluid in our body. Blocking this antidiuretic hormone causes fluids to pass directly through the kidneys to our bladder, which is why we have to pee way more while drinking alcohol. This effect is why alcohol is often thought of as a diuretic. 

Additional ways we can become dehydrated after drinking include vomiting from the alcohol, losing fluids and developing an electrolyte imbalance, and not drinking enough water before or after consuming alcohol. Dehydration is also a common effect of hangovers, and for a more in-depth look, check out our blog: “The Science Behind Hangovers: Why They Last as Long as They Do.”

Signs of Dehydration After Drinking Alcohol

So, we’ve been drinking and are not sure if we’re dehydrated or not. Let’s find out by checking out some of the most common signs of alcohol dehydration:

• We’re thirsty, even after drinking water.
• Our mouth and lips are dry.
• Our urine is a darker color than normal.
• We don’t need to urinate as often as we normally do (this usually happens the day after).
• Our head is throbbing or pounding. 
• We feel tired or lethargic. 
• We feel dizzy or lightheaded.
• Our skin feels dry or lacks elasticity.
• Our heart might be beating faster.
• We throw up or feel nauseous.

If we’re experiencing any of these after excessive alcohol consumption, we could have alcohol dehydration, which can result in serious health consequences.

Factors Influencing Dehydration From Alcohol

We know alcohol can make us dehydrated, but not everyone gets dehydrated at the same rate. Let’s go through some reasons why dehydration from alcohol may impact different people differently. 

• Alcohol content and quantity. The more alcohol we drink, the more dehydrated we will likely get. Alcoholic beverages with higher alcohol content such as liquor tend to dehydrate us more than lighter beverages. 
• Rate of consumption. On average, our body processes about one drink (one beer, one glass of wine, or one shot of liquor) every hour. The faster we drink alcohol, the more we can overwhelm our body, making it harder to process the alcohol as quickly. Binge drinking or consuming multiple drinks in a short amount of time can lead to worse dehydration. 
• Food intake. Eating food alongside alcohol can slow the absorption of alcohol into the bloodstream, which may help reduce dehydration. Eating foods with a high water content such as fruits and vegetables can also reduce alcohol dehydration.
• Environmental factors. Drinking alcohol on a hot, humid day can exacerbate our dehydration. The heat can make us sweat more and cause additional fluid loss.
• Medication and health conditions. If we’re taking diuretic medication, this can compound the diuretic effect of alcohol and lead to more significant fluid loss. Some health conditions such as Crohn’s disease or uncontrolled diabetes can make us lose fluids at a greater rate and can contribute to more fluid loss while drinking. 

All these factors contribute to the severity of dehydration we get after drinking alcohol. So what can we do about it?

What To Do if You’re Dehydrated From Alcohol

We’ve had a night out, and the next morning we wake up and aren’t feeling well. How should we combat our alcohol dehydration? Let’s review some ways we can rehydrate and feel better. 

• Eat. Eating in general can help us, but eating foods rich in fluids such as fruits and vegetables will help hydrate us again. A smoothie can be a great way to get extra fluids and nutrients we need. 
• Drink electrolyte-infused beverages. After drinking, our body loses fluids and electrolytes. Having a drink such as Pedialyte or Liquid IV can help replenish electrolytes and hydrate us at the same time. 
• Avoid more alcohol. We should avoid drinking alcohol until we rehydrate our body and start feeling better. If we have more alcohol, it will make our dehydration worse. 
• Exercise lightly. Light exercise can boost our metabolism and help our body get rid of the alcohol more quickly. 
• Drink water. One of the best ways to rehydrate after drinking is to simply drink water! 

It’s important to rehydrate properly after drinking alcohol. This will allow us to recover and feel better for the day. 

Preventing Dehydration From Drinking

Although we can’t fully prevent dehydration that accompanies drinking alcohol, we can take steps to help our body process the alcohol and lessen the effects of dehydration. Let’s review some things we can do before drinking alcohol to prevent severe dehydration. 

• Eat before drinking. 
• Drink water throughout the day and while drinking.
• Drink slowly.
• Drink in moderation.
• If you are having a mixed drink, choose something that will not further contribute to dehydration. Drinks high in sugar or caffeine can exacerbate dehydration. 

Following these tips can help prevent our dehydration from becoming extreme after drinking.

Key Takeaways

Alcohol dehydrates us through its diuretic effect and contributes to fluid loss through sweating or vomiting. Extreme dehydration for a long period of time can be extremely damaging to our body and can even be fatal. Be sure to stay hydrated throughout the day, and if we’re going to be drinking alcohol, be sure to include water whenever possible.