Caffeine is a stimulant and belongs to the Methylxanthines group, like tea, cola, chocolate, cocoa and some medicines used like analgesics. One normal coffee cup contains 100 to 150 mg of caffeine approximately, for instant coffee its 85 to 100 mg, one cup of tea from 60 to 75 mg, one cola can has 40 to 75 mg and a cup of cocoa has 50 mg.
People react differently to caffeine, small quantities like 250 mg can stimulate excessively to some, to use it often causes tolerance (it requires a bigger quantity of caffeine to achieve the same effect). When ingesting large amounts of caffeine it could lead to intoxication manifested by nervousness, arousal, insomnia, facial flushing, diarrhea, but this seldom happens.
The effects caused in sleep are a vicious cycle, once we wake up after an incomplete sleep cycle, where we didn’t rest, we feel sleepy and therefore we drink coffee ‘to wake up’, but because of coffee, that night our sleep will be irregular again and we wont rest appropriately and will need coffee the next day and so on, developing tolerance where in the future 1 cup wont be enough but two cups will achieve the desired effect.
Pregnant women and kids suffer the effects of caffeine with smaller doses, so we must avoid these beverages, like cola, since they have the same effect.
In some occasions we drink coffee with alcohol, for example in dinners, this combination produces sleepiness because of alcohol, but the effect only lasts 4 to 6 hours, and at midnight the effect fades but coffee’s effect stay, making it difficult to sleep. Same effect happens with sleeping pills mixed with coffee, so we must avoid these combinations.
If you drink 4 or more cups of coffee a day, there’s a dependency on caffeine. It is not advisable to stop drinking immediately because abstinence symptoms will occur like fatigue, somnolence, head aches and flue-like symptoms. These symptoms occur from 18 to 24 hours after the last cup. If you wish to stop drinking coffee it must be done gradually.
If there is somnolence (sleepiness during the day) and you require several cups of coffee, the effect of caffeine could be the root of the issue, as well as snoring, kicking while sleeping, etc., a good start is by quitting coffee and if discomfort continues, seek care by a specialist.