What is the oxygen poor blood?

Few basic reasons: Haemoglobin- a protein molecule, carries o2 in the blood vs called arteries and after o2 is used by tissues, the deoxyg. Hb is carried by vessels called veins -> heart -> lungs to get new o2 molec. Added. When hb is low in quantity or abnl.In str-> o2 is low in blood. Iron, folate, (folic acid) B12 deficiency- anemia o2 defective basic str.As in thalssemia, sicklecell dz. 2.Heart defects->mixing a &venous bloo.

See below: Oxygen is carried in blood by the hemoglobin in rbc's. If hb is low (anemia) the amount of oxygen will be correspondingly low. If exposed to carbon monoxide, oxygen levels can be low because co crowds out the oxygen from the hemoglobin.