2 questions

my almost one year old .  has swcah.  1 question is that he has allways  been in the in the low percentile for his height but now it is starting to drop more now he is in the 2-5 per. different doc’s different per. was wondering if it was anything to be concerned about or not he goes back to the endro on Oct. 30th.
2nd quest. is that he is always thirsty and always has to have something to drink..does that have anything to do with being swcah?