bloated n swollen

there are things happening to mum these couple of weeks that i cannot understand. for example, why did her legs get bloated and swollen a couple of weeks back? and when she went to see the doctor, she was told she had drunk too much water. she was given some medication and everything went back to normal. and then came bloated hands... and today, her face apparently got bloated. and my brother gave her some medications to bring it down. looking at the trend, it seemed rather worrisome. could it be that her kidneys are failing? or could it be related to her heart? or her diet? what other reasons could there be?...

sighs...