regarding the discussion within this thread about pulse oximetry.....i probably wouldnt recommend investing in one. if your respiratory status has decompensated from long term cigarette smoking, to the point where you pulse oximetry readings are significantly lower than that of healthy lungs, when you quit smoking, it may be a very gradual slow increase back to good oxygen saturation levels.it takes a while for the return of healthy lung tissue and good air flow into bronchioles and alveoli,, for the ventilation to perfusion ratio to significantly improve. it's not like blood pressure monitoring, where you start taking an antihypertensive and/or diuretic, and quickly notice changes in BP.
just check your oxygen saturation levels when you go to your primary care provider!
i smoked for 27 years, 1-1.5 packs a day, and quit three weeks ago. my oxygen saturation levels were consistently 98-100% even as a smoker.
disclaimer: i am not a physician and am not giving medical advice. always consult your primary care provider. i am a health care professional however and these are just my thoughts.