Hi Dr, my 10 year old son loves drinking water during the day and also at night, he will only have juice occasionally, however in the last 2-3 weeks he has been complaining saying that even after he drank water at night that he remains thirsty and his mouth still feels try. Should I be concerned, it does not seem normal to be that thirsty all the time. My son is healthy, no medical conditions except for the occasional sinus. Thank you kindly.