Caffeine is one of the most popular stimulants in the world and is also most commonly found in coffee. People use caffeine to wake up in the morning and stay energized throughout the day, but there's a downside: too much caffeine can also keep you awake even when you're ready to fall asleep.
The key to this unwanted aftereffect is a compound called adenosine, which is a byproduct of neuronal activity in the brain. Receptors in our nervous system constantly monitor adenosine levels, and when they drop below a certain point in the brain and spine, the body prepares itself for sleep. Caffeine seeks out specific adenosine receptors and mimics the effects of adenosine, essentially tricking the body into thinking that sleep time is a long way off.
How long caffeine affects the body will vary based on many factors, including tolerance, genetics, and physical health. However, in most cases, these effects last about five to six hours. Long-term coffee drinkers may develop a tolerance to caffeine, which requires them to consume more caffeine to achieve the same stimulating effect. If they suddenly stop drinking coffee, they may experience withdrawal symptoms such as headaches, irritability, and nausea.
To prevent caffeine-related sleep problems, it is recommended to have up to four cups of coffee a day, with the last cup no later than mid-afternoon. Switching to decaffeinated coffee or tea can also help. children and adolescents should avoid consuming large amounts of caffeine.
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