The body is pretty good at keeping an electrolyte to water balance, which is important for nerve conduction and muscle contraction. When you drink alcohol, you may notice that your urine turns clear, a sign that this balance has been disturbed. Here is how it works:

Under normal conditions, the kidneys monitor this balance. As they sense you are becoming dehydrated, the kidneys send a signal to the brain. In turn, the pituitary gland releases antidiuretic hormone (ADH) which tells the kidneys to retain water. Then you will dump some of your electrolytes out when you urinate to restore balance, hence the darker urine color. 

Let’s assume you are in a balanced state of water to electrolytes. As you consume alcohol, it has an effect on the brain, and throws this system out of sorts. It inhibits the release of ADH. Without this important signal, the kidneys do not know to hold on to water, and then you release the fluids you consume through your urine, becoming clearer each time. 

Fast forward to the morning. You’ve depleted your water, but the electrolytes have remained. You are in a salty state. The first time you go to the bathroom, it will be darker than normal as the body is now trying to restore balance. This is likely what causes a hangover; the whole system is dialed down like a dimmer switch. You no longer have adequate water or electrolyte levels. Remember, you need this dial turned up for normal function (especially the brain which is a resource hog-likely the source of headaches). What happens next is a bit of a roller coaster ride.

You’ll probably get up and drink a bunch of water, which is a good thing but now puts you in a state of hyponatremia. This is a state where there is too much water compared to how much salt you have. Hyponatremia will cause a feeling of bloating. Wedding ring suddenly tighter, or swelling in the feet? This can be a sign of hyponatremia and is explained in this article. 

Then perhaps you go out for a nice salty breakfast. You’re craving salt because your body is telling you to restore balance. It’s kind of like driving a truck down the highway and hitting a patch of ice; you swerve and drastically cut the wheel, but overcorrect and swerve the other way back and forth until you finally level out. This is the body trying to restore homeostasis, or balance. 

You can accelerate this process by adding some electrolytes with that water in the morning. That’s why gatorade or pedialyte may make you feel better. However, I prefer to skip the sugar and just add some salt to my water, or use an electrolyte package like LMNT.

If you want the video version of this description: