What are the main signs and symptoms of hangover?

Over 47 symptoms of hangover have been identified. While many hangover symptoms are common, there is immense variation in the subjective experience of hangover: people with hangover may experience any of the hangover symptoms, or any combination of them, to any degree. Among the most common symptoms of hangover are fatigue, thirst, drowsiness, headache, and problems with concentration and memory.^[1]

Physical signs of hangover may include tachycardia (rapid heartbeat), increased blood pressure, tremor, sensitivity to noise and light, and muscle cramps. Sleep disturbances, including an increase in slow-wave sleep and a decrease in both rapid eye movement (REM) sleep and total sleep time, are also associated with hangover.^[2]