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◉ What is RBC in blood test?
RBC (red blood cell) blood test, or RBC count, is a blood test that measures the number of red blood cells in your blood.
Red blood cells carry oxygen from your lungs to every cell in your body. Your cells need oxygen to grow, reproduce, and stay health. Any significant variation in the RBC count can have a profound impact on your health and well-being.
The normal range varies slightly depending on the laboratory and the population being tested but is typically around 4.5 to 5.5 million cells per microliter for men and 4.0 to 5.0 million cells per microliter for women.
An RBC blood test is usually part of a complete blood count (CBC), a group of tests that measure different components and features of your blood.
◉ What are RBCs?
Red blood cells (RBCs), also known as erythrocytes, are a critical component of blood. They are specialized cells that carry oxygen from the lungs to tissues throughout the body and transport carbon dioxide, a waste product, back to the lungs for exhalation.
The main function of red blood cells is to facilitate gas exchange and maintain oxygenation of body tissues.
◉ Structure
Red blood cells are small, biconcave disc-shaped cells that lack a nucleus and most other organelles and contain a red pigment called haemoglobin. This unique structure provides a larger surface area for oxygen and carbon dioxide exchange.
◉ Production
Red blood cells are continuously produced in the bone marrow through a process called erythropoiesis.
◉ Lifespan
The average lifespan of red blood cells is approximately 120 days. After this period, old or damaged red blood cells are removed from circulation by the spleen and liver, and their components are recycled to produce new red blood cells.
◉ Why do I need the RBCs blood test?
A red blood cell count is a test that measures the number of oxygen-carrying blood cells in your blood. It is used to help diagnose red blood cell disorders and it provides valuable information about the overall health and functioning of the circulatory system. Such as:
- Diagnosis of Red Blood Cell Disorders: The test is essential for diagnosing various red blood cell disorders, such as anemia and polycythemia.
- Anemia Assessment: The RBC count is used in conjunction with other tests such as hemoglobin, MCV, MCHC, MCH, and hematocrit to diagnose, classify, and treat anemia.
- Blood Loss Evaluation: The test can help assess the extent of blood loss and guide treatment decisions.
- Monitoring Treatment: If you are receiving treatment that can affect your blood cell counts, such as chemotherapy.
- Evaluation of Chronic Diseases: Monitoring red blood cell counts can aid in the evaluation of conditions, such as kidney disease and bone marrow disorders
- Overall Health Assessment.
◉ Prepare for red blood cells test.
To prepare for a RBC test, you may need to do the following:
- Follow your doctor's instructions about fasting or avoiding certain foods or medications before the test.
- Drink plenty of water before the test to stay hydrated and make it easier to draw blood from your vein.
- Wear Appropriate Clothing like loose-fitting sleeves that can be easily rolled up to allow access to your arm for blood collection.
- Expose your arm for the blood draw
- Relax and breathe normally during the blood draw. You may feel a slight pinch or sting when the needle is inserted, but it should not be too painful or last long.
Note: It's important to note that specific instructions may vary depending on the laboratory or the specific purpose of the blood test. Therefore, it's always advisable to follow any instructions provided by your healthcare provider or the laboratory conducting the test.
◉ What is the normal range of RBCs?
The normal range of red blood cells (RBCs) count varies depending on your age, sex, and altitude of residence.
An RBC count is a blood test that measures the number of RBCs per a particular volume of blood. It may be reported in millions of cells per microliter (mcL) of blood or in trillions of cells per liter (L) of blood.
According to various sources, the normal RBC count for adults is:
- Men: 4.5 to 6.1 million/mcL or 4.5 to 6.1 x 10^12/L
- Women: 4.1 to 5.4 million/mcL or 4.1 to 5.4 x 10^12/L
- The normal RBC count for children is Children: 4.0 to 5.5 million/mcL or 4.0 to 5.5 x 10^12/L
An RBC count that is higher or lower than normal can indicate a medical condition that affects the production or destruction of red blood cells.
◉ High RBCs Count
A high value of red blood cells in the blood is called erythrocytosis or polycythemia. It means that the number of RBCs per microliter of blood is above the normal range.
◉ 1. Causes of High RBCs Count
- 1-Low oxygen levels in the body due to conditions that affect the lungs, heart, or blood vessels, such as chronic obstructive pulmonary disease (COPD), congenital heart disease, pulmonary fibrosis, sleep apnea, or living at high altitudes¹².
- Misuse of certain drugs that stimulate the production of RBCs, such as anabolic steroids, erythropoietin injections, or blood transfusions
- Dehydration, which reduces the plasma volume and makes the blood more concentrated.
- Cancers or pre-cancers that affect the bone marrow, such as polycythemia vera, which causes an abnormal increase in RBCs.
- Kidney diseases or tumors that produce excess erythropoietin, a hormone that regulates RBC production.
- Liver diseases, such as nonalcoholic fatty liver disease, which may also affect erythropoietin levels.
◉ 2. Symptoms of High RBCs count
A high RBC count can cause various symptoms, depending on the severity and the underlying cause.
- Tiredness
- Shortness of breath
- Headaches
- Blurry vision
- Sleep disorders
- Pain
- Joint pain
- Itchy skin
- Numbness and/or tingling
- Nosebleeds
◉ Low RBCs count
A low value of red blood cells (RBCs) in blood is called anaemia. Anaemia is a condition where the blood does not have enough haemoglobin or RBCs to carry oxygen to the body's tissues
◉ 1. Causes of Low RBCs count
1- Nutritional deficiencies:
- Iron deficiency anaemia
- Vitamin B12 deficiency anaemia
- Folate deficiency anaemia
2-Chronic diseases and conditions:
- Chronic kidney disease
- Chronic inflammatory diseases: like rheumatoid arthritis, lupus, or inflammatory bowel disease.
- Chronic infections: Certain infections, such as HIV/AIDS, can lead to anaemia.
3- Hemolytic anemia:
- Autoimmune hemolytic anemia: The immune system mistakenly attacks and destroys RBCs.
- Inherited haemolytic disorders: like sickle cell anaemia or thalassemia.
4- Bone marrow disorders:
- Aplastic anaemia: Damage to the bone marrow, resulting in reduced RBC production.
- Myelodysplastic syndromes: Abnormal development of blood cells in the bone marrow.
◉ 2. Symptoms of Low RBCs count
The symptoms of anaemia can vary depending on its underlying cause, but common symptoms may include:
- Fatigue and weakness
- Pale skin or pallor
- Shortness of breath
- Rapid or irregular heartbeat
- Dizziness or lightheadedness
- Headaches
- Cold hands and feet
◉ What are other analytical tests related to RBC test
In addition to the red blood cell count, there are several other blood tests that are commonly used to assess and diagnose various aspects of anemia and related conditions. These related tests can provide additional insights into the underlying causes and the overall health of the blood and circulatory system
- CBC Blood Test (Complete Blood Count)
- Hemoglobin Blood Test
- Reticulocyte Count
- Hematrocit Blood Test
- Blood Smear
- Iron Test
- Vitamin B12 and Folate Levels
- Bone Marrow Biopsy
- Erythropoietin Levels
- Hemoglobin Electrophoresis
◉ Conclusion
Red blood cell (RBC) tests are commonly used in medical diagnosis to evaluate the quantity, quality, and functionality of red blood cells.
These tests provide valuable information about a person's overall health and can aid in the diagnosis and management of various conditions.