"ogenkidesuka?" this is mean that How are you in Japanese. But if you want to ask about someone's health condition, you can say that, "taityou wa ikagadesuka? or "taityou wa doudesuka? " sentence of " ikagadesuka?" When you buy some clothes in department store in Japan, shop assistant will say to you " ikaga"desuka? It is mean that " is this clothes fit for you?.

well "ikaga desuka" i learn it as um.. look that example : kouhii o mou ippai ikagad desuka ?! (=how about another cup of coffee? ) ikaga desuka= how about . well i'm beginner . and this is all what i learnt so far. but i tape it in google translate and yes , you're right , i found this : ikaga desuka =how are you !

If you want to ask "How are you?" "gokigen ikaga desu ka?" is better.

Well,"i kaga desu ka"="dou desu ka"(how,how about),but "i kaga" sounds more politely.