If you’ve ever had a hangover, you’re surely familiar with the symptoms. The splitting headache, nausea, the forgotten McDonald’s bag on the porch from the night before. We’ve all been there, and it’s not pleasant.
So, what’s the reason we get hangovers, anyway? Many of us have experienced them but never thought about why we actually get those nasty symptoms. Let’s look at why we get hangovers after a night of drinking.
What is a Hangover, Exactly?
To start, we need to understand what a hangover is. A hangover is defined as a set of symptoms that occur when you drink too much alcohol. Hangover symptoms will vary depending on the person, but they can include:
- Dehydration
- Muscle Aches
- Nausea
- Anxiety
- Irritability
What Causes a Hangover?
It can be easy to think a hangover is simply caused by dehydration, but that’s not the case.
Dehydration is one factor, but the main cause of a hangover is how ethanol affects your body.
Hangovers vary from person to person because of genetic factors that decide how you break down acetaldehyde, which is a metabolite of ethanol.
You experience symptoms of a hangover the morning after because of how your enzymes choose to prioritize metabolizing compounds.
When your body has finished metabolizing the ethanol, it moves onto methanol. This is when the hangover symptoms start to kick in. There are several factors that can cause you to experience hangover symptoms.
Your Body Produces More Urine
Alcohol is a diuretic, so you will produce more urine when you’ve been drinking. This can lead to dehydration which makes you thirsty and dizzy.
Alcohol Bothers Your Stomach
When you drink alcohol, your body produces more stomach acid. This delays the stomach from emptying which causes bloating, gas, pain, and vomiting. If you feel uncomfortably full after a night of drinking, this is why.
Drinking Alcohol Can Lower Your Blood Sugar
As your blood sugar levels decrease, you can experience all sorts of unpleasant symptoms. They can range from shaking and fatigue to mood swings. You can even experience seizures.
Your Blood Vessels Can Expand
One of the most common hangover symptoms is the dreaded headache. The headache you experience when you’re hungover is likely from your blood vessels expanding.
It Makes You Tired

Another thing that happens when you drink a lot of alcohol is you get sleepy. The problem is that when you’ve been drinking you won’t be able to reach the deepest stages of sleep.
How often have you gone to bed after a night of drinking and woken up only after a few hours? You will usually wake up exhausted the next day because you didn’t reach a deep sleep cycle.
Final Thoughts
To sum it up, hangovers are never fun. Learning how and why they happen can help you prevent them and manage your symptoms.
It’s always important to understand your limits when it comes to alcohol. Remember, hydrate and drink responsibly. You could also consider investing in hangover recovery pills which you take before drinking to help support your liver.