O 2 dissociation curve shifts to left in acidosis and shifts to right in alkalosis, during hyperventilating states like labor pains, due to pain hyperventilation occurs lead to alkalosis & shift of O 2 dissociation curve occurs accordingly this is first or single Bohr effect this change will cause second change or Bohr effect. Both together called double Bohr effect.

Where and how does second Bohr effect occur in the same patient?