Wildly fluctuating O2 levels

Infact, I bought two oximeters, different brands, to be sure one was not failing. Reading customer comments I saw that they do fail. I have my oxygen levels checked during cardio rehab, and even their more sophisticated oximeter must be held correctly. And I need to take deep breathes. Oxygen levels go down with more exertion because using muscles takes more oxygen - my problem is that it goes down too much

I have the exact same problem. However I was at my dr and brought meter with me and it was the same as the office visit . Mine usually sits at around 89-90. But I have wide fluctuations from 65 to 96 , no blue lips no trouble breathing . My pulse is also low it was 46 when I had those swings I had a pulmonary test last week , wating for the results . Hope that helps ,

My problem has gotten worse in last month...there are some heart issues and fibroisis in lungs causingproblems. I am on Prednizone for 6 weeks to see if that helps.
When I first attach the oximeter, it starts at a low level and then comes up. I don't know if the first reading is me or just the thing booting up.....

First 10 sec of pulse ox are disregarded. I hope it helps.

My problem has gotten worse in last month...there are some heart issues and fibroisis in lungs causingproblems. I am on Prednizone for 6 weeks to see if that helps.
When I first attach the oximeter, it starts at a low level and then comes up. I don't know if the first reading is me or just the thing booting up.....

I have severe hypoxemia which can fluctuate during the day and night. As far as I understand it, an oximeter is not an accurate measuring device for this condition. My lungs are badly scarred and my DLCO was 39% when I had my last breathing test. The reason is that although it shows how much oxygen is carried in your blood cells, it does not mean that that is the amount of oxygen that is utilized by your lungs. You might want to ask your doctor about this and to see if you are retaining C02.

Thanks for your reply. Are you on oxygen? I have been working on understanding my Pulmonary function tests. My DLCO was 55% in April and 52% in December after my 6 weeks on Prednisone for pneumonitis. Mayo is treating my lung cancer, and heart issues, working on determining etiology as that impacts my lung cancer treatments.
I found following on Internet to be able to judge my values:
• Normal DLCO: Between 75% and 140% of the predicted value.
• Mildly reduced DLCO: 60% to 75% or the lower limit of normal (LLN) predicted value.
• Severely reduced DLCO: Less than 40% of the predicted value.

Is there another term for Dlco? I have my PFT open and I don’t have a result with that label.

It appears under Diffusion. But they don't always measure it. I had one test where they did not do it.