right hypoplastic kidney

my name is Vinay, i have been suffering from pain in the right lower abdomen, it was diagnosed as accute appendicitis, any how escaped surgery later by CAT scan it was diagnosed i had right hypoplastic kidney. I still suffer from the pain + burning sensation in waist, back of both legs, some times burning while urinating.

Kindly let me know what does it mean to have hypoplastic kidney...