Hemoglobin is a protein found in red blood cells. The purpose of hemoglobin is to carry oxygen from the lungs to the other tissues and cells of the body. A complete blood count determines the amount of hemoglobin in the blood and the number of red blood cells in the body. A test of the hemoglobin is usually used to monitor or diagnose conditions such as anemia or polycythemia. A hemoglobin test will also provide information about the need for blood transfusions.
A hemoglobin test may be performed if signs and symptoms include:
Fatigue
Malaise
Fainting
Pallor
Shortness of breath
Dizziness
Headache
Enlarged spleen
Difficulty with vision
A hemoglobin test will be able to provide the doctor with an overall assessment of health.