a finger pulse ox level can be adversely affected if you do not have adequate blood going to the fingers for whatever reason. blood oxygen can be tested on the toes and even the earlobes depending on the machine. it can even be tested from a more invasive arterial blood specimen but this is rarely done anymore. you can buy your own pulse ox machine that goes on your finger relatively inexpensive now in some pharmacies and even at costco!
how do you measure blood oxygen levels what equipment is used and is it used only on fingers? . if blood ox is measured from fingers does poor to bad circulation in the fingers have a negative effect on the reading?