KK,
OK, I'll try to make it simple.
A number of the chemical reactions in the human body which sustain the processes of life are dependent on there being adequate levels of CO2. In the breathing process, what U need is a BALANCE between the levels of O2 & CO2 (not a rise in CO2). If an imbalance occurs, then all the functions of breathing become disturbed.
Most people whose body, mind or spirit is out of balance will hyperventilate or overbreathe with lots of short chest breaths that leave them DEPLETED of CO2 => O2 level too high => imbalance, which tends to increase (& become dangerous !) if U don't do anything about it.
What U want to do to solve the problem is REDUCE the loss of CO2 (by regulating your breathing) or INCREASE your CO2 level (by breathing in a bag for example).
MF