Anemia: What My Red Blood Cell Count Tells Me
Anemia is a condition where the number of red blood cells in the body falls below normal. This may happen if the body slows down its production of these cells. Losing large amounts of blood is another cause of anemia.
Red blood cells carry vital oxygen throughout the body and remove carbon dioxide. Carbon dioxide is deadly if too much is present, and without enough oxygen, the body cannot function.
There are many reasons why people become anemic. It may be hereditary, caused by an infection or chronic disease in the body, or result from bleeding. It may be caused by a lack of iron or other nutrients, or be a side effect from cancer or cancer treatments.
Anemia is very common in people with cancer. Cancer treatments, including radiation and some types of chemotherapy, can affect the bone marrow where red blood cells are made. After these treatments, the bone marrow either slows down or temporarily stops making red blood cells. The cancer itself may also prevent the bone marrow from making blood cells.
Although anemia is rarely fatal, its symptoms can severely hinder one's ability to do everyday activities. Fortunately, it can be successfully treated in most cases.
There are certain conditions that are more likely to cause anemia. People who have colorectal cancer may lose blood in their stool and not even know it. Leukemia and lymphoma can also disrupt blood cell production.
Some cancers require chemotherapy drugs that inhibit the growth of red blood cells. As long as a person gets these drugs, they will be at risk for anemia.
The most obvious symptom of anemia is fatigue. This is a tiredness that does not get better with rest or sleep.
Other symptoms include dizziness, increased heart rate, headaches, loss of appetite, having a hard time concentrating, and shortness of breath -- especially after physical activity. Fewer red blood cells in the body mean less oxygen, which can affect breathing.
Your doctor may order a complete blood count test (CBC) and other lab tests to diagnose anemia. They may include:
How am I feeling?
You may not feel any differently if your anemia is mild. But as the number of red blood cells drops lower, the more symptoms that will likely appear.
The amount of blood loss and how quickly it is lost affect the degree of symptoms.
I've been diagnosed with anemia: now what?
The next step is for your doctor to find out the underlying cause. Only then can the healthcare team effectively treat it.
Doctors may have different approaches to which lab tests are used to find the cause of the anemia. Most look at hemoglobin and hematocrit first. If those are low, they look at more specific labs such as iron, folate, or vitamin B12. These nutrients are directly involved with making red blood cells. If you have low levels of these, your doctor may give vitamin or mineral supplements or injections, which usually cure the anemia--if this is the main cause.
Treating anemia caused by cancers or cancer therapies is more complicated. Certain forms of leukemia or lymphoma directly attack red blood cells in the bone marrow. In addition, treating these cancers with chemotherapy or radiation can further suppress the growth of blood cells. A bone marrow transplant, blood transfusions, or growth factors may be needed in these cases.
Are blood transfusions safe?
Severe anemia is usually corrected with a transfusion of red blood cells. This is when blood is transferred through tubes into a person's vein. The blood may be the person's own blood or from someone else.
There is ongoing concern about the risk of infection from transfusions. The scare began in the early 1980s with the emergence of the AIDS epidemic.
But today donated blood is screened for AIDS and other viruses by looking for antibodies (special proteins) in the blood. The odds are in the patient's favor in the U.S. today as the blood supply is relatively safe. Still, the risk has not been completely eliminated.
Allergies are another concern. The more transfusions you get over time, the more likely you are to develop an allergic reaction. The symptoms vary but might include a rash, high fever, or shaking and chills. If a reaction does occur, there are various methods to control the reaction. Special filters for the blood may be used, or the patient may be given an antihistamine, such as diphenhydramine (Benadryl). In addition, medical centers often transfuse cancer patients using irradiated blood. Radiating the blood before the transfusion kills certain components in the blood that can cause allergic reactions.
There are some conditions that will require long-term blood transfusions. Myelodysplasia and myelofibrosis are diseases of the bone marrow that block normal blood cell activity. Frequent transfusions increase the risk for allergic reactions and infections. They can also be costly and cause anxiety for the patient.
An alternative to blood transfusions
Erythropoietin has been popular as an alternative to transfusions. It is a growth factor and natural hormone made in the kidneys. Erythropoietin stimulates red blood cells to grow. Procrit is one brand name of a lab-created form of erythropoietin called epoetin alfa. Another long-acting one is Aranesp (darbepoetin alfa). These are approved for patients with anemia caused by chemotherapy. Growth factors may even prevent the need for transfusions altogether in some people.
Growth factors may not work or be appropriate for everyone and they cannot cure disease or prevent an underlying disease from progressing.