How does caffeine keep us awake?

Caffeine is a stimulant that can make us feel more awake and alert by blocking the action of a neurotransmitter called adenosine in the brain. Adenosine is a naturally occurring chemical that accumulates in the brain over the course of the day, causing drowsiness and promoting sleep.

When we consume caffeine, it enters the bloodstream and crosses the blood-brain barrier, where it binds to and blocks the adenosine receptors in the brain. This action prevents adenosine from binding to its receptors and signaling the brain to slow down, allowing us to feel more awake and alert.

In addition to blocking adenosine, caffeine also triggers the release of other neurotransmitters such as dopamine and norepinephrine, which can increase alertness, mood, and cognitive performance.

However, it is important to note that excessive caffeine consumption can have negative effects on health and well-being, including anxiety, jitteriness, disrupted sleep, and dependence. It is recommended that adults limit their caffeine intake to no more than 400 mg per day, which is roughly equivalent to 4 cups of coffee