Here’s what happens to your body when you have a hangover, and the chemical effect behind dehydration, headache, fatigue, and vomiting.
Alcohol causes dehydration as it blocks your body’s release of an antidiuretic hormone, which is usually used to help your kidneys conserve water. Without this hormone, your kidneys can’t save the water the way they’re supposed to, causing increased urine production.
This doesn’t just explain why you constantly feel the need to urinate while intoxicated—it also explains thirst. Urinating too frequently causes your body to lose fluid, leading to more dehydration.
Alcohol stimulates the release of serotonin and dopamine, two of your neurotransmitters—the body’s chemical messengers. These neurotransmitters also cause feelings of euphoria but altered levels of serotonin and dopamine are known to cause headaches.
Your headache might also come from dehydration.
Here's how alcohol before bed causes fatigue and impairs and worsens a nights sleep:
- It disrupts REM sleep—the most restorative type of sleep. When you don’t get enough REM sleep, you might wake up feeling tired.
- It increases the production of adenosine. This is a chemical that helps you fall asleep quickly. However, the adenosine also subsides quickly, which can make you wake up before you’re fully rested.
- It turns on a sleep pattern called alpha activity, which puts your body in a state of rest rather than into the deep sleep it needs.
When your body processes alcohol, acetaldehyde is the first byproduct and acetaldehyde is a toxic compound that’s known to cause sweating, nausea, and vomiting.
Alcohol can provoke a release of cytokine - small proteins used by the immune system to fight infection. This release of cytokines causes nausea.