To me, "Are you okay?" implies more concern than "How's it going?" or "How are you?". I only hear it from people who know me well and are looking for a real answer. "Everything going okay?" falls into the almost meaningless greeting category, though.

So, what does "okay" mean to me? It doesn't mean "no problem" because BP is a problem that never really goes away. But sometimes the monster is sleeping and that's okay. Sometimes it's awake but I am putting up a good fight; that's shoulder shrug "okay, I guess". Sometimes I am in the belly of the beast and that most certainly is not okay.