The reason why you can’t sleep after drinking too much coffee is because caffeine has the effect of exciting the central nervous system. If being more sensitive to caffeine can cause insomnia, this condition is not a cause for much concern because of specific intervening factors. As long as the patient abstains from coffee, the symptoms can usually be relieved within two to three days. Patients should also avoid any foods or beverages that contain caffeine, such as chocolate and strong tea, which may also cause insomnia. If symptoms persist after three days of coffee withdrawal, it is considered that it may not be related to the direct effect of caffeine. Patients need to visit a neurologist or psychiatrist to improve the relevant scale assessment to clarify whether there is mental anxiety, tension or poor mood or depression leading to insomnia. If the score is above 40, the use of relevant medication should be considered.