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Microcytic Anemia

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Introduction to Blood Diseases

Any disorder of the blood involving red blood cells (erythrocytes), white blood cells (leukocytes), or platelets (thrombocytes) or the tissues that produce these elements—the bone marrow, lymph nodes, and spleen — or bleeding and blood clotting is known as blood disease. 

Even before the origin and composition of blood were understood, disordered blood was blamed for a wide range of symptoms. Red blood cells were not discovered until the 17th century, and it took another 100 years for one of the forms of white blood cells, the lymphocyte, to be discovered, as well as blood clotting (coagulation). Other types of leukocytes were discovered in the 19th century, and a number of diseases of the blood and blood-forming organs were identified. In the nineteenth century and the first quarter of the twentieth century, morphological changes — changes in shape and structure — that occur in the blood during disease, as well as the signs and symptoms of various blood diseases, were identified. In the years since, a more physiological approach has emerged, focusing on the processes underlying the development of blood disease and the methods for correcting abnormalities.

In the diagnosis of blood disease, some aspects of the physical examination are particularly relevant. These involve pallor, red tongue, and enlargement of the heart, liver, spleen, or lymph nodes; tiny purple patches or larger bruises on the skin; and bone tenderness.

Microcytic Anemia 

Red blood cells that are smaller than average are referred to as microcytosis. Anaemia is a condition in which the body has a reduced number of properly working red blood cells.

Your body has fewer red blood cells than normal if you have microcytic anaemia. It doesn't have enough red blood cells, and the ones it does have are too few. Microcytic anaemia refers to a number of different forms of anaemia. Microcytic anaemia is caused by a disorder in which the body is unable to produce enough haemoglobin. Haemoglobin is a substance found in your blood. It aids in the delivery of oxygen to your tissues and is responsible for the red colour of your red blood cells.

The majority of microcytic anemia is caused by an iron deficiency. Iron is needed for the production of haemoglobin in your body. Microcytic anemia can be caused by a variety of factors. Your doctor will first diagnose the root cause of your microcytic anaemia before treating it.

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Microcytic Anemia Symptoms

At first, you do not find any signs or symptoms of microcytic anaemia. When the tissues are affected by a lack of normal red blood cells, symptoms frequently occur at a later stage.

Fatigue, exhaustion, and tiredness are common symptoms of microcytic anaemias.

  • fatigue, weakness, and tiredness

  • loss of stamina

  • shortness of breath

  • dizziness

  • pale skin

Make an appointment with your doctor if you have any of these symptoms and they don't go away after two weeks. If you are experiencing extreme dizziness or shortness of breath, you should see your doctor as soon as possible.

Microcytic Anaemia Causes and Types

Microcytic anaemias are classified based on the amount of haemoglobin present in the red blood cells. They may be hypochromic, normochromic, or hyperchromic, depending on the situation:

1. Hypochromic Microcytic Anaemias

Hypochromic red blood cells have less haemoglobin compared to normal red blood cells. Your red blood cells can look paler in colour due to low haemoglobin levels. Your body has low numbers of red blood cells that are both smaller and paler than usual if you have microcytic hypochromic anaemia.

Hypochromic anaemia is the most common form of microcytic anaemia. The following are examples of hypochromic microcytic anaemias: Anemia due to a lack of iron: An iron deficiency in the blood is the most common microcytic hypochromic anaemia causes. Anaemia due to iron deficiency can be caused by a variety of factors, including:

  • Inadequate iron intake, usually as a result of your diet

  • being unable to consume iron due to conditions such as celiac disease or infection with Helicobacter pylori.

  • Chronic blood loss in women due to severe or frequent cycles, or GI bleeds from upper GI ulcers or inflammatory bowel disease.

  • Pregnancy

Thalassemia is a type of anaemia caused by an inherited defect. It is caused by mutations in genes that are required for normal haemoglobin development. Sideroblastic anaemia is a form of anaemia that can be passed down through generations due to gene mutations (congenital). It may also be triggered by a later-life disorder that prevents the body from integrating iron into one of the components required to produce haemoglobin. Iron builds up in the red blood cells as a result of this. Microcytic and hypochromic anaemia is common in congenital sideroblastic anaemia.

2. Normochromic Microcytic Anemias

Your red blood cells are Normochromic if they have a normal amount of haemoglobin and the colour of blood isn't too pale or dark. The following is an example of normochromic microcytic anaemia: Inflammatory anaemia and chronic disease: These types of anaemia are commonly normochromic and normocytic (red blood cells are normal in size). People with Normochromic Microcytic Anemia may have:

  • infectious diseases, such as tuberculosis, HIV/AIDS, or endocarditis

  • inflammatory diseases, such as rheumatoid arthritis, Crohn’s disease, or diabetes mellitus

  • kidney disease

  • cancer

These conditions can prevent red blood cells from functioning normally. This can lead to decreased iron absorption or utilization.

3. Hyperchromic Microcytic Anemias

Hyperchromic refers to the presence of more haemoglobin in red blood cells than is usual. Red blood cells with high levels of haemoglobin have a darker red colour than average.

Hyperchromic microcytic anaemia is a rare congenital spherocytic anaemia. They may be affected by congenital spherocytic anaemia, a genetic disorder. Hereditary spherocytosis is another name for this condition.

The membrane of your red blood cells does not shape properly in this disorder. They become rigid and spherical in form as a result of this. They are sent to the spleen to be broken down and die since they do not move through the blood cells properly.

4. Other Causes of Microcytic Anemia

Other causes of microcytic anaemia include:

  • lead toxicity

  • copper deficiency

  • zinc excess, which causes copper deficiency

  • alcohol use

  • drug use

Macrocytic Hypochromic Anemia

When an RBC is macrocytic, it has larger cells than a normal cell, and hypochromic meaning - it has less colour than a normal RBC. Folate deficiency, vitamin B12 deficiency, or some chemotherapeutic agents can cause hypochromic macrocytic anaemia; and vitamin B12 deficiency can cause pernicious anaemia.

Macrocytic Anemia Symptoms

You may not notice any symptoms of macrocytic anaemia until you’ve had it for some time.

Symptoms include:

  • loss of appetite or weight

  • brittle nails

  • fast heartbeat

  • diarrhoea

  • fatigue

  • pale skin, including lips and eyelids

  • shortness of breath

  • poor concentration or confusion

  • memory loss

Normocytic Hypochromic Anemia 

Hypochromic Normocytic anaemia is a form of anaemia that affects men and women over the age of 85. Its prevalence rises with age, hitting 44% in men over the age of 85. Anaemia with chronic disease is the most common form of normocytic anaemia.

When the red blood cells are of normal size, it is called normocytic anaemia. The mean corpuscular volume (MCV) is described as being between 80 and 100 femtolitres (fL), which is within the usual and expected range. The hematocrit and haemoglobin, on the other hand, are reduced. Microcytic anaemias are defined as anaemia with a mean corpuscular volume (MCV) of less than 80 fL and macrocytic anaemias with an MCV of more than 100 fL.


The issue is thought of as representing any of the following:

  • An acute loss of blood of a substantial volume;

  • a decreased production of normal-sized red blood cells (e.g., anaemia of chronic disease, aplastic anaemia);

  • Increased production of HbS as seen in sickle cell disease (not sickle cell trait);

  • Increased destruction or loss of red blood cells (e.g., hemolysis, posthemorrhagic anaemia, hypersplenism);

  • an uncompensated increase in plasma volume (e.g., pregnancy, fluid overload);

  • a B2 (riboflavin) deficiency

  • a B6 (pyridoxine) deficiency

  • or a mixture of conditions producing microcytic and macrocytic anaemia.

Do You Know?

Q: Is Hypochromic Microcytic Anaemia Transferred Hereditarily?

A: In both childhood and adulthood, microcytic anaemia is the most common form of anaemia. Microcytic anaemias are highly heterogeneous and can be acquired (most often due to iron deficiency) or inherited.

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FAQs on Microcytic Anemia

1. What are the Most Common  Microcytic Hypochromic Anemia Causes?

Answer. A lack of iron Hypochromic microcytic anaemia is caused by a disruption of iron supply in the diet due to low iron content, small intestine pathologies such as sprue and frequent diarrhoea, gastrectomy, and a vitamin C deficiency in the diet.

2. What are Some of the Causes of Hypochromic Anaemia?

Answer. Vitamin B6 deficiency, which can result from a low iron intake, reduced iron absorption, or excessive iron loss, can cause hypochromic anaemia. Infections (e.g. hookworms) or other illnesses (e.g. chronic disease anaemia), therapeutic medications, copper toxicity, and lead poisoning can also cause it.

3. How are Microcytic Hypochromic Anaemias Diagnosed?

Answer. Look for a bleeding trigger in microcytic hypochromic anaemia. Serum iron level and TIBC, as well as serum ferritin level or stain of bone marrow specimen for iron, are all suitable for the laboratory tests.