Around here it depends on that little person who checks (shortly after you come in) your blood pressure, temperature, and to see if you are currently in pain.
When I went to a hospital ER last December for chest pains, when I received the little persons interview and checks, I had no current pain at the immediate time.
After 9 hours of me & wife waiting to be called, I went to the desk and said that I was going outside and call 911 so that an ambulance would bring me in to get fast treatment like I observed. In 5 minutes they took me through the ER doors, and it was later discovered that I needed a 'stint' placed inside a vein of my heart.
So, it depends on the condition at the time of appearing as to how long you wait around here.