Anemia is a condition that develops when your blood lacks enough healthy red blood cells or hemoglobin. Hemoglobin is a main part of red blood cells and binds oxygen. If you have too few or abnormal red blood cells, or your hemoglobin is abnormal or low, the cells in your body will not get enough oxygen. Symptoms of anemia — like fatigue — occur because organs aren’t getting what they need to function properly.
Anemia is the most common blood condition in the U.S. It affects about 3.5 million Americans. Women, young children, and people with chronic diseases are at increased risk of anemia. Important factors to remember are:
- Certain forms of anemia are hereditary and infants may be affected from the time of birth.
- Women in the childbearing years are particularly susceptible to iron-deficiency anemia because of the blood loss from menstruation and the increased blood supply demands during pregnancy.
- Older adults also may have a greater risk of developing anemia because of poor diet and other medical conditions.
There are many types of anemia. All are very different in their causes and treatments. Iron-deficiency anemia, the most common type, is very treatable with diet changes and iron supplements. Some forms of anemia — like the anemia that develops during pregnancy — are even considered normal. However, some types of anemia may present lifelong health problems.
Normally low hemoglobin counts
A slightly low hemoglobin count isn’t always a sign of illness — it may be normal for some people. Women who are pregnant commonly have low hemoglobin counts.
Low hemoglobin counts associated with diseases and conditions
A low hemoglobin count can be associated with a disease or condition that causes your body to have too few red blood cells. This can occur if:
- Your body produces fewer red blood cells than usual
- Your body destroys red blood cells faster than they can be produced
- You experience blood loss
Diseases and conditions that cause your body to produce fewer red blood cells than normal include:
- Aplastic anemia
- Certain medications, such as anti-retroviral drugs for HIV infection and chemotherapy drugs for cancer and other conditions
- Hodgkin’s lymphoma (Hodgkin’s disease)
- Iron deficiency anemia
- Chronic kidney disease
- Lead poisoning
- Leukemia and other diseases that damage bone marrow
- Multiple myeloma
- Myelodysplastic syndromes
- Non-Hodgkin’s lymphoma
- Vitamin deficiency anemia
Diseases and conditions that cause your body to destroy red blood cells faster than they can be made include:
- Enlarged spleen (splenomegaly)
- Sickle cell anemia
A low hemoglobin count can also be due to blood loss, which can occur because of:
- Bleeding from a wound
- Bleeding in your digestive tract, such as from ulcers, cancers or hemorrhoids
- Bleeding in your urinary tract
- Frequent blood donation
- Heavy menstrual bleeding
Anemia Caused by Destruction of Red Blood Cells
When red blood cells are fragile and cannot withstand the routine stress of the circulatory system, they may rupture prematurely, causing hemolytic anemia. Hemolytic anemia can be present at birth or develop later. Sometimes there is no known cause. Known causes of hemolytic anemia may include:
- Inherited conditions, such as sickle cell anemia and thalassemia
- Stressors such as infections, drugs, snake or spider venom, or certain foods
- Toxins from advanced liver or kidney disease
- Inappropriate attack by the immune system (called hemolytic disease of the newborn when it occurs in the fetus of a pregnant woman)
- Vascular grafts, prosthetic heart valves, tumors, severe burns, exposure to certain chemicals, severe hypertension, and clotting disorders
- In rare cases, an enlarged spleen can trap red blood cells and destroy them before their circulating time is up.
Risks of Anemia in Pregnancy
Severe or untreated iron-deficiency anemia during pregnancy can increase your risk of having:
- A preterm or low-birth-weight baby
- A blood transfusion (if you lose a significant amount of blood during delivery)
- Postpartum depression
- A baby with anemia
- A child with developmental delays
Untreated folate deficiency can increase your risk of having a:
- Preterm or low-birth-weight baby
- Baby with a serious birth defect of the spine or brain (neural tube defects)
Untreated vitamin B12 deficiency can also raise your risk of having a baby with neural tube defects.
Donors Deferred for Low Hemoglobin
If you’re not eligible to give blood because of low hemoglobin
If you were deferred, for low hemoglobin, there may be steps you should take before you try to donate again.
It is important for blood donors to understand how hemoglobin may be affected by the level of iron in your blood. Read below to learn more detailed information.Low Hemoglobin / Hematocrit
The hemoglobin test measures the amount of a protein called hemoglobin that carries oxygen in your red blood cells. We check your hemoglobin at every donation and it must be above the minimum value required for blood donation which is 12.5g/dLHow iron deficiency is detected and diagnosed
The tests used most often to detect iron deficiency include hemoglobin (the iron-containing protein in the blood that carries iron and oxygen to cells), hematocrit which provides the percentage measures of of red blood cells in the blood, serum ferritin, which indicates the amount of iron stored in the body, and serum iron and iron-binding capacity (IBC, UIBC or TIBC). The latter measures are used to calculate transferrin-iron saturation percentage (TS%), a measure of iron in transit in the serum. Serum ferritin is a very important test because it helps distinguish between iron deficiency anemia and anemia of chronic disease (also called anemia of inflammatory response). In cases of iron deficiency anemia, iron supplements can be helpful; but in cases of anemia of chronic disease, iron supplements could be harmful.
Other tests might include: a complete blood count, zinc protoporphyrin, free erythrocyte protoporphyrin or reticulocyte hemoglobin content (CHr). To learn more about these tests visit tests to determine iron levels.
A diagnosis of iron deficiency can be made when a person has both low hemoglobin and hematocrit and low serum ferritin. Serum iron and, transferrin-iron saturation percentage will also be low in a person who is iron deficient. Iron deficiency without anemia can occur when a person has a normal hemoglobin, but below normal serum ferritin and/or transferrin saturation. Iron deficiency with anemia can occur when a person has low values of both serum ferritin and hemoglobin.
How iron deficiency is treated
The approaches used to treat iron deficiency depend on the presence or threat of anemia and its causes, which may be increased demand for iron (pregnancy, growth spurt), blood loss (heavy periods, giving birth, surgery, injury, disease), diet or behavior, interference with iron absorption, and abnormal blood cell formation or management. Some approaches are as simple as dietary changes and others involve taking iron supplements, which are available in heme and non heme form. Some people with significant iron deficiency might require iron infusions or whole blood transfusions to restore iron sufficiency.
If you suspect that you are iron deficient, we encourage you to work with a medical professional to find out why your are iron deficient and then to increase your knowledge about the different ways low iron stores can be replenished. Visit the our Iron library, in the getting started section and read the Anemia Starter Kit. Then, you can evaluate the best approaches to replenish iron levels.
Make an appointment if you have signs and symptoms
If you experience signs and symptoms of a low hemoglobin count, make an appointment with your doctor. Signs and symptoms may include:
- Pale skin and gums
- Shortness of breath
- A fast or irregular heartbeat
Your doctor may recommend a complete blood count test to determine whether you have a low hemoglobin count or whether your signs and symptoms are caused by something else.
If your test reveals you have a low hemoglobin count, you will likely need more testing to determine the cause. Then your doctor can explain what this means for you.