Hemoglobin is the pigment that makes blood red. It also transports oxygen from our lungs to the cells in our body. The hemoglobin molecule contains iron, an essential mineral found in our diet.
What Are Normal Hemoglobin Levels?
Normal hemoglobin levels are different in women and in men. In non-pregnant women, normal hemoglobin ranges from 120 g/L to 160 g/L. In men, normal hemoglobin levels range from 140 g/L to 180 g/L. Canadian Blood Services tests each donor’s hemoglobin at the clinic and requires a minimum of 125 g/L for donation. Starting on March 5, 2017, male donors will be required to be at a minimum of 130 g/L for donation, female donors will remain at 125 g/L minimum.
Why Does Canadian Blood Services Measure Hemoglobin Level?
We measure hemoglobin to protect you as a donor, and to ensure the quality of the red blood cells that will be transfused into blood recipients. Your hemoglobin level drops off temporarily after you donate blood. If you have normal iron reserves and adequate iron in your diet, new red blood cells will be made and your hemoglobin level will return to normal. It is important not to donate blood if the hemoglobin level is already low.
How Is Hemoglobin Measured?
We check each donor’s hemoglobin level at the clinic before every donation. A sterile, single-use device called a lancet is used to obtain a drop of blood from your finger. The blood sample is tested using a machine that determines the hemoglobin level.
What If I Don't Meet Minimum Hemoglobin Criteria?
Many donors with borderline low hemoglobin will be eligible on their next attempt to donate, so please come back and try again. Sometimes donors who do not meet minimum hemoglobin criteria may also have anemia, which may indicate more serious medical problems. You can read more about anemia below.
Typically, about 10 percent of female donors do not meet minimum hemoglobin criteria on any given donation day. It is quite rare for male donors to have a hemoglobin level below the minimum blood donor criteria.
If your hemoglobin is below the acceptable level, see your doctor for further testing for anemia and to determine the underlying cause.
I Am A Healthy Female Donor, But Seem To Fail My Hemoglobin Test Every Second Time. What Should I Do?
If your physician has not found any medical problem but you have borderline hemoglobin results and are often below the acceptable level for donation, we recommend donating blood less often to maintain better iron stores. For example, if you come to donate every 84 days and fail your finger stick hemoglobin test every second time, we suggest changing your donation routine to once every six months. As well, try to increase your iron intake. See the iron needs for blood donors section of our site for more information.
What Is Anemia?
Mild anemia is most often due to low iron reserves. Borderline anemia may indicate a lack of iron in your diet. In women, normal iron loss in menstrual periods and during pregnancy may also be factors. However, anemia may be a sign of more serious conditions as well. It can be related to poor absorption of iron from food caused by celiac disease, for example. It could also be due to increased blood loss from stomach ulcers, polyps, or even cancer of the colon—which can be very gradual and not noticeable on a daily basis.
If your hemoglobin level is below 110 g/L, you should see your physician for further testing. If anemia is present, you should not return to donate until the cause of the low hemoglobin has been identified and corrected.
Can Donating Blood Cause Anemia?
Frequent blood donation does contribute to iron loss and anemia. Whole blood donation results in a drop in hemoglobin of approximately 10 g/L (approximately 6 to 8 percent), depending on the size of the donor. Normal, healthy donors produce new red blood cells to replace donated cells. However, iron is essential to the production of new red blood cells, meaning if your iron levels are low, your body may have more difficulty replenishing your red blood cells. That’s why it’s so important for donors to have an adequate amount of iron. Frequent donors (men who donate three or more times a year and women who donate two or more times a year) may need iron supplements to make up for iron lost in donations.