How does caffeine affect the body?

Caffeine acts primarily as a central nervous system stimulant. When you consume it, it travels through your bloodstream to the brain, where it has a few key effects:

• Blocking Adenosine: Throughout the day, your body builds up a chemical called adenosine, which makes you feel tired. Caffeine is chemically similar to adenosine and binds to those same receptors in your brain, effectively "blocking" the signal that tells your body it's time to sleep.
• Increased Alertness: By blocking adenosine and stimulating the release of neurotransmitters like dopamine and norepinephrine, caffeine can help improve focus, mood, and perceived energy levels.
• Physical Effects: It can increase your heart rate and blood pressure, stimulate the digestive tract (which is why it often acts as a mild laxative), and act as a diuretic, meaning it can slightly increase the frequency of urination.
• Adrenaline Release: It can trigger the adrenal glands to release adrenaline, often referred to as the "fight or flight" hormone, which contributes to the jittery feeling some people get after too much coffee.

Because it affects everyone differently, factors like your individual metabolism, regular intake, and sensitivity to stimulants determine how strong these effects feel. If you consume it too late in the day, the blocked adenosine receptors can make it harder to fall asleep or get deep, restorative rest.