o2 saturation

I am 50, female and smoke a pack of cigs a day. i tend to get  small amounts of mucous in my bronchi and i make myself cough versus having to...i have allergies and every morning i have postnasal drip with thick mucous..my nose is always stuffed...i occassionally wheeze but it tends to clear with coughing ...i was able to check my oxygen recently with an o2 sat machine and it reads  94-96% sitting or standing...the problem is when i lie down it goes down to  90-94% (i can feel a little lightheaded  sometimes too)...if i make myself cough,once or twice, and bring up small amts of mucous, it goes up to 97-98 but then goes back down to 94-96 if im sitting..then 90-94 if laying down, but will go up again with a couple of coughs to 97 or 98%...if i walk up and down the stairs a few times, my oxygen goes up to 98% then again comes back down....besides needing to quit smoking is this a sign of copd, chronic broncitis, asthma, emphysema or what and what is a normal o2 sat?  i did have a cold a few weeks ago but it didnt turn into a chest cold just a stuffy nose with a little cough Do i need to be worried with these numbers?  thank you for your time and response

[National Jewish]

Normal oxygen levels depend on altitude.  The normal saturation at sea level is 96-98%.  At 5,280 feet, it is 92-94%.  Yes, your borderline levels could be a sign of COPD or emphysema.  The change in saturation probably relates to the movement of mucous within your lungs, or a shift in blood flow to parts of your lungs that have been damaged by cigarette smoke.   And, yes, you should definitely stop smoking.
This is a golden opportunity for you to save your lungs while there is still time.  Any damage that has already occurred cannot be reversed, but by quitting smoking the progression of COPD will slow down.  Please take this warning seriously and stop smoking now.  At this time quitting smoking is the most important thing that you can do for yourself!  You may want to look at our Quit Smoking Topic Center at http://www.nationaljewish.org/topic/smoking_cessation.html for ways to help you become smoke free.  Also check with your doctor for other quit smoking resources in your area.

[starion]

Sounds like time to go to your doctor & get a thorough evaluation to see whether you currently have a lung condition that should be treated.  Your doctor can start with a spirometry test and then decide whether a full pulmonary function test is needed.

In any case, you already undoubtably know that the BEST thing you can do for your lungs, body & life is quit smoking.  This is more than any doc or med can do (though the doc can help you if YOU want it).

Best of luck!
Starion