What does a low hemoglobin level mean? (from medicinenet.com)

http://www.medicinenet.com/hemoglobin/page2.htm

By Medical Author:
Siamak T. Nabili,MD, MPH
Medical Editor:
William C. Shiel Jr., MD, FACP,FACR

What does a low hemoglobin level mean?

A low hemoglobin level is referred to as anemia or low red blood count. Lower than normal number of red blood cells is referred to as anemia and hemoglobin level reflects this number. There are many reasons for anemia.

Some of the more common causes are:

• loss of blood (traumatic injury, surgery, bleeding, colon cancer or stomach ulcer),
• nutritional deficiency (iron, vitamin B12, folate),
• bone marrow problems (replacement of bone marrow by cancer),
• suppression by chemotherapy drugs,
• kidney failure, and
• abnormal hemoglobin structure (sickle cell anemia or thalassemia).