The oxyhemoglobin dissociation curve relates the percentage saturation of hemoglobin with the partial pressure of oxygen (pO2).
It tells about the affinity of hemoglobin for oxygen.
It can be used to ascertain the effects of pCO2 and H+ concentration on the binding affinity of hemoglobin for oxygen.
The strength by which oxygen binds to hemoglobin is affected by several factors and can be represented as a shift to the left or right in the oxygen dissociation curve.
A rightward shift of the curve indicates that hemoglobin has a decreased affinity for oxygen, thus, oxygen actively unloads.