7 Types of Anaemia

Summary

This video explains how anemia is diagnosed and categorized based on the mean cell volume (MCV) of red blood cells. The script explores three types of anemia: microcytic anemia, caused by iron deficiency or thalassemias; macrocytic anemia, resulting from defective DNA synthesis due to deficiencies in B12 or folate; and normocytic anemia, primarily due to blood loss. It also discusses the role of chronic inflammation in iron deficiency and the impact of certain drugs or conditions like celiac disease on red blood cell production. The video aims to provide a clear understanding of the various causes of anemia and how MCV can help identify them.

Takeaways

• 😀 Red blood cell (RBC) volume, measured by MCV (Mean Cell Volume), helps determine the cause of anemia.
• 😀 Low MCV indicates microcytic RBCs, often due to iron deficiency or thalassemia.
• 😀 Thalassemia is a genetic disorder leading to abnormal hemoglobin synthesis, causing smaller RBCs.
• 😀 Chronic inflammation (e.g., Crohn's disease, rheumatoid arthritis) can cause iron deficiency anemia, referred to as anemia of chronic inflammation.
• 😀 High MCV indicates macrocytic RBCs, which result from impaired DNA synthesis.
• 😀 Vitamin B12 and folate deficiencies can lead to macrocytic anemia, particularly in malnourished individuals or those with celiac disease.
• 😀 Intrinsic factor, produced in the stomach, is essential for B12 absorption, and its deficiency can lead to pernicious anemia.
• 😀 Excessive alcohol intake can disrupt folate levels, contributing to macrocytic anemia.
• 😀 Certain drugs, such as chemotherapy and HIV medications like AZT, can interfere with DNA synthesis, leading to macrocytic anemia.
• 😀 Normocytic anemia, where RBC size is normal, often results from blood loss, rather than a deficiency or DNA issue.

Q & A

What is MCV, and how is it calculated?

MCV (Mean Cell Volume) is a value that helps determine the average volume of a person's red blood cells. It is calculated by dividing the total volume of red blood cells in a sample by the overall concentration of red blood cells in the mixture.

How does MCV help in diagnosing anemia?

MCV helps identify the cause of anemia by determining whether the red blood cells are too small or too large. A low MCV indicates microcytic anemia, while a high MCV indicates macrocytic anemia.

What happens if a person has low MCV?

Low MCV indicates that the red blood cells are smaller than normal, which is often caused by a lack of hemoglobin. This can be due to iron deficiency or genetic conditions like thalassemia.

Why does iron deficiency lead to microcytic red blood cells?

Iron is a crucial component of hemoglobin. When there is not enough iron, the body cannot produce enough hemoglobin, leading to smaller red blood cells (microcytic RBCs).

What is thalassemia and how does it relate to anemia?

Thalassemia is a genetic disorder that causes a dysfunction in hemoglobin synthesis, leading to small red blood cells and a type of anemia known as microcytic anemia.

What is anemia of chronic inflammation?

Anemia of chronic inflammation occurs when the liver holds onto iron stores due to inflammation, preventing its use in red blood cell production. This condition is common in diseases like Crohn's disease and rheumatoid arthritis.

What causes macrocytic anemia?

Macrocytic anemia is caused by defects in DNA synthesis. When DNA replication is impaired but hemoglobin continues to be produced, it results in large, swollen red blood cells.

What role do vitamin B12 and folate play in red blood cell production?

Vitamin B12 and folate are essential for DNA synthesis in red blood cell precursors. A deficiency in either can result in macrocytic anemia due to impaired DNA replication.

How can celiac disease contribute to macrocytic anemia?

Celiac disease damages the distal ileum in the small intestine, where vitamin B12 is absorbed. This leads to reduced B12 uptake, increasing the risk of macrocytic anemia.

What are some drugs that can cause macrocytic anemia?

Certain drugs, like chemotherapy agents (e.g., methotrexate, AZT) and some HIV medications, can interfere with DNA synthesis, leading to macrocytic anemia.

What is normocytic anemia and what is its most common cause?

Normocytic anemia occurs when the red blood cells are of normal size but the overall number of red blood cells is insufficient. The most common cause is blood loss.