Which of the following is not a symptom of a hangover?

In the context of hangovers, increased energy is not a typical symptom. Hangovers arise after heavy drinking and manifest through a variety of unpleasant physical and mental symptoms caused by dehydration, electrolyte imbalance, and the effects of alcohol on the body. Common symptoms include headaches, fatigue, and nausea, which align with the body’s reaction to the aftereffects of alcohol consumption.

A headache is often experienced due to dehydration and chemical changes in the brain, while fatigue is a result of poor sleep quality and the body's efforts to recover. Nausea occurs as the body reacts to toxins and the lingering effects of alcohol on the gastrointestinal tract. In contrast, increased energy would imply an elevated level of alertness or physical vitality, which is not characteristic of a hangover experience. Thus, identifying increased energy as not a symptom accurately reflects the typical aftereffects of alcohol consumption.