People have long wondered about the exact scientific causes of a hangover, and over the years, scientists have pinpointed many separate factors that play a role. Alcohol has the potential to cause severe dehydration, and this is considered one of the main causes of a hangover. Some of the other symptoms are generally caused by the innate toxicity of alcohol and the difficulties it causes for the body, including various digestive problems. Another factor that might be one of the most crucial causes of a hangover is withdrawal from alcohol, which may occur after the body has been exposed to too much in a single sitting. For unknown reasons, some people seem to be totally immune to hangovers, while others suffer terribly after only consuming one or two drinks.
Since alcohol is basically toxic, it can only be processed by the liver, and many experts think this is one of the primary causes of a hangover. The liver helps in keeping the blood stream clean of toxins, and it's also involved in keeping blood glucose levels balanced. Consuming alcohol overwhelms the liver, which keeps it from performing its basic functions at peak efficiency, leading to a large variety of unpleasant symptoms. The relation to blood glucose levels may be the reason why some of the symptoms associated with hangovers are actually similar to things people experience with type II diabetes.
When people consume a lot of alcohol, they also tend to urinate a lot more frequently. This leads to dehydration, which can cause many of the symptoms related to a hangover. In fact, one of the most common remedies for a hangover is for people to focus on rehydrating the next morning. It won't get rid of every symptom, but it can potentially be helpful. Alcohol also has a tendency to irritate the stomach, which can cause vomiting, nausea, and many of the other unpleasant symptoms generally associated with hangovers.
Some experts believe that one of the primary causes of a hangover is withdrawal from alcohol. Like many other drugs, consumption of alcohol can lead to a certain level of physical dependence, and the hangover is thought to possibly be a consequence of that. This may be one of the reasons for the so-called "hair of the dog" remedy, since consuming more alcohol while suffering from a hangover can sometimes lessen symptoms. Most experts agree this is probably a temporary effect that is far outweighed by the potential for more severe hangover symptoms later on.
