What would be the consequences of a deficiency of haemoglobin in our bodies?

The haemoglobin is responsible for the transportation of oxygens to the cells in the different part of the body.
The deficiency of the haemoglobin in the blood of a person reduces the oxygen-carrying capacity of the blood resulting in the improper supply of oxygen to the tissue of the body which results in breathing problems, tiredness and lack of energy. The person looks pale and loses weight.