one of the reasons why caffeine may be making your thirsty is because caffeine is a diuretic meaning that it can make you urinate more frequently. as a result dehydration and increased thirst may occur if your body is getting rid of too much fluid. caffeine isn’t a strong diuretic so there is typically a net gain in water retention if you only consume a moderate amount of caffeine but large enough doses could dehydrate you though your individual response and caffeine-sensitivity may vary. diuretics can also be used as a medication for heart-related conditions like high blood pressure so your symptom of feeling thirsty may be worse if you’re on this medication or one with similar side effects. also depending on what you’re consuming say coffee or tea you could also be experiencing astringency from the naturally occurring bitter plant compound called tannin. astringency can be described as the dry puckering sensation in your mouth that you get by consuming tannin which might be making you feel thirsty. coffee is typically low in tannin content but tea especially black tea is high in tannins.
why does caffeine make thirsty?