Yes, it makes you light headed due to lack of oxygen. There is a simple blood test doctors can do to determine the level of CO2 blood gasses. However, you will have to request this test, it is not done on a routine basis. Have the test done after you have been up and about for a long time because respiration calms down when you sleep at night and the CO2 balance will be better early in the morning. Our activity and breathing will deplete it later in the day.
Shortness of breath is a symptom also.
Hope this is of help to you and others, at least to know it does exist and doctors do not look for it. See my note about this today.