Hi again, PK2018, and thanks for your question - it is a good one!
The answer to your question will depend on what type of spirometer you have in mind. No matter which spirometer you plan on buying, I would suggest you discuss this with your physician. Your physician will be able to guide you as if you should have one to work with.
I say this because the most common spirometer which is out there is called an 'incentive spirometer'. This is a spirometer that is typically used for 'inspiratory exercise' most commonly following abdominal or even thoracic surgical procedures. It is designed so the patient will inhale to a certain level (measured in milliliters). Once the goal (or 'incentive'😉 is reached, the patient can be moved on to the next level.
There are also spirometers that are designed to measure one's exhaled volume. These can be used for any number of reasons. This is the typical style spirometer (although much more sophisticated), that is used to provide a diagnostic pulmonary function test (PFT).
Again, I would suggest you start out by discussing this with your physician. Once you have a recommended spirometer in place, please do let us know. We can assist you further as necessary.
What do you think?
Leon (site moderator COPD.net)