Drinking water at night

The only reason I can think of is the excess need for urination. Hopefully, if you had to go then you would wake up. If not, then you could end up holding it all night long and actually damage your bladder over time.

first i would have to ask why were u adviced that?? was it a casual advice or were u having some health problems and so were adviced for that?? and the last thing was it a doctor that adviced u that??

depending on things there can be various reasons. might be u dont get sleep well becoz u r getting up all the time for drinking and so let u have a good sleep they must have adviced u that . or may be ur depending on physical condition ur docstor must have adviced u that, for that u can have may reasons.
i have also read in some articles that water is the cause for increasing obesity. weird though it is true . they are advicing to drink juice or health drink instead .

The reason why we need to lessen our drinking water at night is that we are bothered by urination. We have to pee everytime. And our sleep sacrifice because of this. The best way to avoid this is 3-4 hour before you sleep you already drink water.