Flexible Economy is a new enhanced Economy service operating on a single cabin aircraft for customers on our shorthaul network flying to and from London Heathrow.
Although caffeine is generally safe and well tolerated, it can cause side effects when ingested in large doses. Additionally, regular caffeine use can cause dependency, resulting in withdrawal symptoms when caffeine is not consumed. Headaches can be a symptom of either too much caffeine or too little.
Caffeine is a diuretic, so causes dehydration, which in turn causes headaches. This could be due to the brain, which is 80 per cent water, shrinking and pulling away from the skull, triggering pain receptors.