Definition

Erythrocytes, commonly referred to as red blood cells, are a vital component of the human circulatory system. These cells are produced in the bone marrow and released into the bloodstream once mature. Erythrocytes possess a distinctive biconcave shape (concave on both sides) and contain hemoglobin, the red pigment crucial for their function. This unique shape enables erythrocytes to flexibly navigate through the bloodstream, ensuring efficient oxygen and carbon dioxide transport. Hemoglobin plays a central role in gas exchange. Erythrocytes carry carbon dioxide produced by the body to the lungs, where it is exchanged for oxygen. The carbon dioxide binds to lung cells and is expelled through respiration, while oxygen-rich erythrocytes travel back into circulation to supply body tissues with energy.

Given these essential roles, it is crucial for erythrocytes to remain healthy and functional. Healthy erythrocytes have a normal shape, adequate hemoglobin levels, and sufficient maturity, ensuring they can perform optimally.

The number of erythrocytes in the body can be measured through a red blood cell test. This test helps determine whether the count is within the normal range. Regular red blood cell tests are often recommended by healthcare providers to assess a patient’s overall health or diagnose specific medical conditions.

Indications

There are several medical conditions that necessitate a red blood cell (erythrocyte) test, including:

• Anemia, characterized by symptoms such as fatigue, pale lips, dizziness, rapid heart rate, and cold sweats.
• Instances of bleeding, whether visible or hidden.
• Before undergoing a blood transfusion.
• Chronic infections such as parasitic infestations or tuberculosis.
• Chronic illnesses like kidney failure, cancer, inflammatory bowel disease, or autoimmune conditions.
• Pregnancy.
• Malnutrition.
• Diseases of the spinal cord.
• Tumors.
• Chronic obstructive pulmonary disease (COPD).

Contraindications

There are no specific conditions that outright prevent a red blood cell test. However, certain medications may interfere with the test results. It is important to inform your doctor about any medications you are taking, as they can impact the accuracy of the results.

Medications that may lower red blood cell counts include those used in chemotherapy, chloramphenicol, quinidine, and hydantoin. On the other hand, drugs like gentamicin, methyldopa, and diuretics may increase red blood cell counts. For this reason, consulting with your doctor prior to the test is essential. Your doctor may recommend adjusting or temporarily discontinuing these medications to ensure accurate results.

Preparation Before the Test

No extensive preparation is needed before undergoing a red blood cell test. However, the following steps are recommended:

• Ensure you get adequate rest.
• Maintain regular eating and drinking habits.
• Avoid smoking.
• Provide your doctor with a list of all medications you are taking so they can determine if these drugs may affect the test results. If necessary, your doctor will advise on the best time for the test or suggest temporarily stopping certain medications.

Test Procedure

A red blood cell test involves analyzing a blood sample. The process begins with laboratory personnel locating a vein for the blood draw. The site is cleaned with antiseptic, and a strap is applied to make the vein more prominent. A syringe is then inserted into the vein to collect the blood sample. Once the required amount of blood is collected, the strap is removed, and the syringe is withdrawn. The puncture site is cleaned with an antiseptic or alcohol swab and pressed to stop any further bleeding. The blood sample is subsequently analyzed in the laboratory to determine red blood cell levels.

Normal and Abnormal Values

Normal Values

The normal range of red blood cell counts depends on factors such as age and gender. The following are the normal values of this test:

Table 1: The Normal range values ​​for the number of erythrocytes in human serum

(Source: Cafasso, J. (2022). Red Blood Cell (RBC) Count. Healtline. Revieved May 19, 2022, from https://www.healthline.com/health/rbc-count)

Abnormal Values

Abnormal results occur when red blood cell counts fall below or rise above the normal range. The cause of elevated RBC counts include congenital heart disease, spinal cord disorders, COPD, tumors, dehydration, heavy smoking, or hypoxia due to insufficient oxygen. Meanwhile, the cause of reduced RBC counts include anemia, undetected bleeding, malnutrition, chronic infections, chronic diseases like kidney failure or cancer, and pregnancy.

Results and Recommendations (Further Testing)

Normal

If your erythrocyte test results fall within the normal range, this indicates that your red blood cell count is healthy, and you can continue maintaining a balanced lifestyle to support your overall health.

Below Normal

If the erythrocyte test results are below normal, it is essential to identify the underlying cause. The doctor will consider the symptoms you are experiencing, any physical abnormalities noted during the examination, and the results of your erythrocyte test. If anemia is suspected based on these factors, the doctor may recommend additional tests, such as a complete blood count, iron profile, and peripheral blood cell analysis using a microscope. Anemia can be caused by several factors, including iron deficiency, folate or vitamin B12 deficiency, or blood loss. Further tests, such as a chest X-ray, stool analysis, complete urine test, kidney function tests, and malignancy marker screening, may also be recommended to pinpoint the exact cause of the low erythrocyte count.

Above Normal

If your erythrocyte test results indicate a higher-than-normal count, various medical conditions could be responsible. These include polycythemia vera, increased erythrocyte production in the spinal cord, chronic obstructive pulmonary disease (COPD), congenital heart disease, dehydration, tumors, or heavy smoking. To determine the cause of the elevated erythrocyte count, your doctor may recommend further tests, such as a complete blood count, spinal cord tissue analysis, chest X-ray, spirometry, cardiac ultrasound, tissue biopsy, or electrolyte examination. Early detection and treatment of the underlying condition are crucial.

Consult the Right Doctor

If your erythrocyte test results are either below or above normal, it is essential to consult with an internal medicine specialist. Early diagnosis will help determine the medical condition you may be experiencing, allowing for prompt treatment.

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