A Closer Look At Your Lab Test Results
Getting a CBC is simple. A nurse or other member of your healthcare team takes a sample of blood from your arm and sends it to the lab for testing. The lab measures the different components in your blood and sends the report back to your doctor. Often, your doctor provides you with a copy as well.
Your doctor goes over the results with you and explains what they mean. Each lab is different. Labs usually vary a little in what they consider a normal range. On the results, the lab should define what the normal range is next to what your measured range is. It should indicate if your count is high or low so that you can ask your doctor questions about what that means for your health.
Why Your Healthcare Provider Checks Your Rbc Count
Your healthcare provider will check your red blood cell count routinely, as part of your annual exam. Because RBCs play such an important role in overall health, checking their levels annually can offer early signs of any underlying health issues. Your provider also might test your RBC count if you have signs and symptoms of a blood-related health disorder. Fatigue and shortness of breath, for example, can indicate iron-deficiency anemiaa very common cause of low red blood cell counts.
Why It Is Done
A complete blood count may be done to:
- Find the cause of symptoms such as fatigue, weakness, fever, bruising, or weight loss.
- Check for anemia.
- Diagnose diseases of the blood, such as leukemia.
- Check how the body is dealing with some types of drug or radiation treatment.
- Check how abnormal bleeding is affecting the blood cells and counts.
- Screen for high and low values before a surgery.
- See if there are too many or too few of certain types of cells. This may help find other conditions, such as too many eosinophils may mean an allergy or asthma is present.
A complete blood count may be done as part of a regular physical examination. A blood count can give valuable information about the general state of your health.
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When To Contact A Doctor
In some people, dietary and lifestyle changes will not be enough to manage RBC levels.
A doctor may prescribe certain medications to stimulate the production of RBCs. They may recommend hormone treatment to people with anemia due to cancer, kidney disease, or any other disorder that may have caused a hormonal malfunction.
If tests show that the persons low RBC count is due to a different cause, doctors will attempt to treat the underlying condition. Treatment may help the RBC count improve on its own. Diet and lifestyle choices can also support specific treatments.
A doctor may rarely recommend a red blood cell transfusion if RBC levels do not respond to medications and lifestyle changes.
Why Normal Ranges Can Differ Across Different Labs
Each laboratory must establish its own normal ranges for RBC count in the blood. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels, according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.
Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.
There are some circumstances that can alter the normal ranges:
- RBC are increased 0.15 to 0.25 million/ µl per km of altitude
- In post-menopause women, there is an increase in RBC normal range to be similar to men ranges.
- Above 65 years old there is a progressive reduction in the RBC count for both genders.
- During pregnancy, RBC count is lower than normal and the normal count is specific for each trimester of pregnancy.
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What Is The Normal Count Of Rbc In The Blood
RBC count ranges depend on gender and age according to the following table:
- Adult men: 4.5 6.2 million/µl
- Adult women: 4 – 5.5 million/µl
- Boys from 15 to 17 years old: 4.3 5.7 million/µl
- Girls from 15 to 17 years old: 3.8 5 million/µl
- Children from 11 to 14 years old: 4.1 5.3 million/µl
- Children from 6 to 10 years old: 4.1 5.2 million/µl
- Children from 3 to 5 years old: 4.0 5.1 million/µl
- Children of 2 years old: 3.8 5 million/µl
- Babies from 6 months old to 2 years old: 3.9 5.1 million/µl
- Babies from 8 weeks old to 5 months old: 3.4 4.8 million/µl
- Babies from 5 weeks old to 7 weeks old: 2.9 4.2 million/µl
- Babies from 2 weeks old to 4 weeks old: 3.1 4.8 million/µl
- Newborns : 4.1 5.7 million/µl
Other Tests For Evaluation Of Anemia
Serum bilirubin and lactate dehydrogenase can sometimes help differentiate between hemolysis and blood loss both are elevated in hemolysis and normal in blood loss. Other tests, such as vitamin B12 and folate levels and iron and iron binding capacity, are done depending on the suspected cause of anemia. Other tests are discussed under specific anemias and bleeding disorders.
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Dependence Of Hematologic Parameters Of Sex
Men and women have different mean hemoglobin levels in health in venous blood women have mean levels approximately 12% lower than men. Since no difference is noticed in the level of erythropoietin with different sexes, the difference in the intensity of erythropoiesis comes from the physiological changes in the kidneys not in bone marrow . There is no evidence showing reduced cellular mechanisms for hem synthesis in women, and there is no difference in the iron absorption between women and men . The established reference ranges for woman are under the influence of large proportion of those with iron deficiency. . The difference in hemoglobin concentration regarding sex has not been found in infants and preschool children , but it has been shown in teenagers and adolescents . In our research, we compare the hematological parameters with male and female examinees, as well as whole groups regardless of their age. The male examinees showed significantly higher values of RBC higher values of Hb Hematocrit . The average size of red blood cells and medium content of Hb in them insignificantly higher with the boys. Due to the similar size of the cells and higher total amount of hemoglobin with the males, MCHC, concentration of Hb in erythrocyte, is higher with the boys . The size span of erythrocytes is wider with the girls which lead to bigger variability of the erythrocytes size.
What Abnormal Results Mean
Higher than normal numbers of RBCs may be due to:
- Cigarette smoking
- Problem with heart’s structure and function that is present at birth ( congenital heart disease
- Failure of the right side of the heart ( cor pulmonale
- Low blood oxygen level
- Scarring or thickening of the lungs ( pulmonary fibrosis
- Bone marrow disease that causes abnormal increase in RBCs ( polycythemia vera
Your RBC count will increase for several weeks when you are in a higher altitude.
Drugs that can increase the RBC count include:
Lower-than-normal numbers of RBCs may be due to:
- Bone marrow failure
- Deficiency of a hormone called erythropoietin
- RBC destruction due to transfusion, blood vessel injury, or other cause
- Too much water in the body
Drugs that can decrease the RBC count include:
- Chemotherapy drugs
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Errors In Red Blood Cell Count
RBC counts may be falsely elevated due to increased RBC or WBC fragments or cryoglobulins. Increased large platelets may also cause a spuriously high RBC count, as the enlarged platelets are counted as RBCs due to increased volume . RBC counts may be falsely decreased due to microcytosis in this case, the small RBCs are counted as platelets by the analyzer. Similarly, increased RBC fragments, or schistocytes, may be incorrectly counted as platelets . RBC clumps can also cause a spuriously low RBC count .
Anne Provencher Bolliger, Nancy Everds, in, 2012
What Does Hematocrit Mean
Hematocrit is the percentage by volume of red cells in your blood. Blood is made up of red blood cells, white blood cells and platelets, suspended in plasma. Together, those comprise about 45% of the volume of our blood, but the specific percentages of each can vary.
What Is a Hematocrit Level?
Hematocrit level is simply the percentage of red cells in your blood. For example, a level of 38% is considered the minimum needed for donating blood.
What Is Normal Hematocrit?
Normal hematocrit levels vary based on age and race.. In adults, normal levels for men range from 41%-50%. For women, the normal range is slightly lower: 36%-44%. A hematocrit level below the normal range, meaning the person has too few red blood cells, is called anemia. A hematocrit level above the normal range, meaning too many red blood cells, may indicate polycythemia or erythrocytosis.
Why Should You Test Hematocrit Levels?
Your doctor may test your hematocrit levels if you show signs of having anemia, polycythemia or erythrocytosis. Symptoms of anemia include fatigue, shortness of breath and dizziness. Symptoms of polycythemia include fatigue, itching, headaches, and sweating. Symptoms of erythrocytosis includes headaches, dizziness, shortness of breath, and nosebleeds.
What Is the Difference Between Hematocrit and Hemoglobin
Hematocrit and hemoglobin measurements are both blood tests but they are not testing the same thing.
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What Is The Rbc Count Used For
RBC count is used to know the overall health status, the possible existence of an anemia, a general disease or a cancer.
The RBC count test should be studied for a better diagnosis along with other blood tests such as the hemoglobin, the hematocrit, MCV , MCH and MCHC .
A low RBC count, called erythrocytopenia, usually comes with a low hemoglobin level in the blood in what is called anemia. There are different types of anemia for example, iron deficiencyanemia , megaloblastic anemia or hemolytic anemia . Aplastic anemia where the bone marrow does not produce enough new blood cells also cause erythrocytopenia.
Another possibility for a low RBC count is an excessive bleeding or kidney disorders that may reduce the production of erythropoietin hormone.
The RBC count may be elevated for many pathologic reasons. Erythrocytosis may be:
- Relative: There is a decrease in blood plasma, maybe due to dehydration, and therefore the RBCs are more concentrated in the blood.
- Absolute: It implies that it is a true increase in RBC count and it is usually due to a genetic disorder called polycythemia vera.
Respiratory diseases that cause tissue hypoxia increase the secretion of erythropoietin and therefore an increase in RBC.
What Is A Normal Rbc Range
Your red blood cells transport oxygen to cells of the body. An RBC count is the number of red blood cells per a particular volume of blood. It may be reported in millions of cells per microliter of blood or in trillions of cells per liter of blood.
The “normal” or “reference” range can sometimes vary depending on whose blood is being tested. If you live in a high-altitude city like Denver, your blood count will be far higher than people who live in low-altitude areas like the Gulf Coast.
This is because when you are at a higher altitude, your body creates more red blood cells so that more oxygen can be carried to your tissues. For this reason, the ranges cannot be considered hard-and-fast values but just a reference point.
The RBC count reference range varies by sex and age:
- Women: 4.2 to 5.4 million/mcL
- Men: 4.7 to 6.1 million/mcL
- Children: 4.1 to 5.5 million/mcL
Anything above these RBC levels may be concerning.
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What Affects The Test
Reasons you may not be able to have the test or why the results may not be helpful include:
- If the elastic band was on your arm a long time while the blood sample was taken.
- Taking medicines that can cause low platelet levels. Some examples of the many medicines that cause low platelet levels include steroids, some antibiotics, thiazide diuretics, chemotherapy medicines, quinidine, and meprobamate.
- A very high white blood cell count or high levels of a type of fat . These can cause falsely high hemoglobin values.
- Having an enlarged spleen, which may cause a low platelet count or a low white blood cell count. An enlarged spleen may be caused by certain types of cancer.
- Pregnancy, which normally causes a low RBC value and less often a high WBC value.
How To Manage High Rdw Levels
Unless your RDW levels are due to a chronic illness or hereditary condition, lifestyle and dietary changes can proactively help lower the levels.
If you are at risk of having high RDW levels, heres what you can do:
Focus on your diet Often, nutrient deficiency can lead to low RDW levels. So, a potent deficiency of iron, folate, and Vitamin B12 can trigger the change in shape and size of the RBCs. In that case, supplementing your diet with the proper nutrients is crucial.
Quit smoking and alcohol Studies suggest that people who smoke have higher tendencies of having elevated RDW levels. Also, alcohol can inadvertentlydamage the RBCs in the bloodstream. So, avoid both of them.
Get quality sleep Disrupted sleeping patterns can significantly lower the RDW levels, as reported in astudy with 17,000+ participants.
Get active It is scientifically proven that people that lead a lazy and sedentary lifestyle have higher RDW levels. So, instead, focus on getting active and exercising to lower the levels.
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What Does A Cbc Look For
A CBC does many tests to measure and study red blood cells, white blood cells and platelets. Red blood cells carry oxygen throughout the body. White blood cells are part of your immune system. They help your body fight infection. Platelets help your body clot.
A CBC measures, counts, evaluates and studies many aspects of your blood:
- CBC without differential counts the total number of white blood cells.
- CBC with differential. There are five kinds of white blood cells. The differential looks at how many of each kind of white blood cell you have.
- Hemoglobin tests measure hemoglobin, the protein in red blood cells that carries oxygen.
- Hematocrit describes the concentration of red blood cells in your blood.
A CBC tells your provider:
- How many new blood cells your body is creating.
- Number of red blood cells , white blood cells and platelets.
- Size and shape of blood cells.
Treatment For A High Rbc Count
If you have erythrocytosis, you may need a regular phlebotomy. This removes a small amount of blood from your body in order to lower your RBC count.
If phlebotomies dont work, your doctor may prescribe hydroxyurea to reduce your RBC count.
You may also need aspirin to help with potential blood clots.
Lifestyle changes can affect your RBC count. Some changes that can help increase your RBC count include:
- maintaining a healthy diet and avoiding vitamin deficiencies
- exercising regularly, which requires the body to use up more oxygen
- avoiding aspirin
If you need to decrease your RBC count, the following lifestyle changes may help:
- reducing the amount of iron and red meat that you consume
- drinking more water
Why The Test Is Performed
The RBC count is almost always part of a complete blood count test.
The test can help diagnose different kinds of anemia and other conditions affecting red blood cells.
Other conditions that may require an RBC count are:
- Bone marrow disorder in which the marrow is replaced by scar tissue
- Disease that damages kidney blood vessels
- Disorder in which red blood cells break down earlier than normal
- White blood cell cancer
If My Rbc Count Is Out Of Range What Other Tests Might Be Done
An RBC count can be used to detect a problem with red blood cell production and/or lifespan, but it cannot determine the underlying cause. In addition to the full CBC, some other tests may be performed at the same time or as follow up to help establish a diagnosis. Examples include:
- Blood smeara laboratory professional examines the blood under the microscope to confirm results of a CBC and/or to look abnormal blood cells
- Reticulocyte countdetermines the number of young red blood cells
- Iron studiesiron is important in the production of red blood cells
- Vitamin B12 and folate levelsthese vitamins are also important for red blood cell production
- In more severe conditions, a bone marrow aspiration and biopsyusually done by a pathologist to help detect abnormalities in the bone marrow and determine the cause of low or high blood cell counts or abnormal blood cells
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Bone Marrow Aspiration And Biopsy
Bone marrow aspiration and biopsy provide direct observation and assessment of RBC precursors. The presence of abnormal maturation of blood cells and the amount, distribution, and cellular pattern of iron content can be assessed. Bone marrow aspiration and biopsy are usually not indicated in the evaluation of anemia and are only done when one of the following conditions is present:
More than one cell lineage abnormality
Suspected primary bone marrow disorder
Cytogenetic and molecular analyses can be done on aspirate material in hematopoietic or other tumors or in suspected congenital lesions of RBC precursors . Flow cytometry can be done in suspected lymphoproliferative or myelodysplastic states to define the immunophenotype. Bone marrow aspiration and biopsy are not technically difficult and do not pose significant risk of morbidity. These procedures are safe and helpful when hematologic disease is suspected. Bone marrow aspiration and biopsy are usually can be done as a single procedure. Because biopsy requires adequate bone depth, the sample is usually taken from the posterior iliac crest. If myeloma is suspected or there is severe osteoporosis, an ultrasound-guided biopsy is done because it is the safest to avoid penetrating the pelvis.