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How does caffeine affect you?
When you drink a cup of coffee, the drug it contains – caffeine – takes effect within minutes. It then blocks chemical signals in your brain, stopping you from feeling sleepy. In moderate doses caffeine also improves mental ability – reaction times, memory and reasoning skills. It takes your body 3–5 hours to break down caffeine, which is why coffee at bedtime may stop you sleeping.
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The drug caffeine stops you from feeling sleepy.
Is caffeine addictive?
Caffeine is addictive. Even if you drink only one large cup of coffee (or three cans of a cola drink) per day, you may feel the ill effects of missing a 'dose'. The symptoms of caffeine withdrawal include headaches, drowsiness and loss of concentration. Drinking coffee will relieve these symptoms, so it can become compulsive. Caffeine in high doses can make anyone anxious but, in vulnerable people, even one cup of filter coffee can result in symptoms similar to a panic attack.
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