You might be quite aware of the fact that hangovers are pretty sure to come while you are drunk. But have you ever thought about the reason for this? Hangovers happen due to the consumption of too much alcohol. However, to some people, even a very little amount of alcohol can result in a hangover. Hangovers occur as a result of alcohol triggering an inflammatory response from your immune system. Your immune system may trigger certain agents that commonly produce physical symptoms, such as an inability to concentrate, memory problems, decreased appetite, and loss of interest in usual.