Dry mouth from drinking is mainly caused by water exudation, vasodilation and urination. 1. Water exudation: due to the high concentration of alcohol, after the alcohol enters the blood, it will make the water inside the cell permeate to the outside of the cell, resulting in part of the water stored in the body being excreted to the outside of the body, resulting in a lack of water. 2. Vasodilatation: alcohol, also known as ethanol, enters the body after metabolism will become acetaldehyde, acetaldehyde has the effect of vasodilatation, resulting in a decrease in the effective circulating blood volume, the symptoms of thirst. 3. Urination: large amounts of alcohol will accelerate the urinary capacity of the kidneys, urination increases, a large amount of water discharge, the body will feel thirsty. It is recommended to replenish water in time after drinking, and if you feel unwell, you should go to the local formal medical institutions for further treatment.