How much life expectancy is there once level 5 on continuous oxygen is reached?

Stacy, I would not want to give you a false idea of what level 5 means.....You'd have to talk to a medical professional to find out how often it indicates that the end of life is drawing near. I I will tell you about what happened in our case.--- My mother had always been at around level 2 to 3 on her oxygen, and then it started being right around 3 for quite a while. Then things took a turn for the worse and she had to go up to level 5. She was starting to really weaken at that point and she was nearing the end of her life. A nurse or doctor could help you understand what this level means in the case of your loved one. My best to you.

If you are on level 5 can you go back down to a 3

Lots depends on her general condition. I have seen it go up to 10 litres and that needs two concentrators. people you think are close to the end can often hang on for many weeks it is totally unpredictible, you just have to take it one day at a time.