Anemia - The functional disorders of RBC

Definition of Anemia :

The disorders of Red blood cells is called as by the term “Anemia.” Any Red blood cell disorder that impacts on the body is known as Anemia.

Anemia means deficiency of hemoglobin in the blood, which can be caused by either two few red blood cells or two little hemoglobin in the cells.

Anemia diminishes the capacity of the blood to carry oxygen. Patients with anemia may feel tired, fatigue easily, appear pale, develop palpitations and become short of breath.

Classification of Anemia: 

Anemia is be classified in two types:

1. Morphological Classification

2. Etiological Classification

MORPHOLOGICAL CLASSIFICATION

The morphological classification depends upon the size and color of RBC. By this method, anemia is classified into four types:

1. Normocytic Normochromic Anemia:
Size or mean Corpuscular volume (MCV) and color or Mean Corpuscular Hemoglobin Concentration (MCHC) of RBC’s are normal.

But the number of RBC is less

2. Macrocytic Normochromic Anemia:
RBCs are larger in size with normal color. RBC count is
less.

3. Macrocytic Hypochromic Anemia
RBCs are larger in size. MCHC is less, so the cells are
pale (less colored).

4. Microcytic Hypochromic Anemia
RBCs are smaller in size with less color.

 

ETIOLOGICAL CLASSIFICATION

On the basis of etiology (the study of cause or origin), anemia is divided into five types:

1. Hemorrhagic anemia:  Anemia due to hemorrhage is known as hemorrhagic anemia. 

2. Hemolytic anemia: Anemia due to excessive hemolysis which is not compensated by increased RBC production is called hemolytic anemia. 

It is further classified into two types: Extrinsic hemolytic anemia and Intrinsic hemolytic anemia.

3. Nutrition deficiency anemia: Anemia that occurs due to deficiency of a nutritive substance necessary for erythropoiesis is called nutrition deficiency anemia. It is further classified into four types:

1. Protein deficiency anemia: Due to deficiency of proteins, the synthesis of hemoglobin is reduced. The RBCs are macrocytic and hypochromic. It is known as protein deficiency anemia.

2.Iron deficiency anemia: Deficiency of Iron substance in RBC

3.Pernicious anemia or Addison’s anemia: Pernicious anemia is the anemia due to deficiency of vitamin B12. 

It is also called Addison’s anemia. It is due to atrophy of the gastric mucosa because of autoimmune destruction of parietal cells 

4.Megaloblastic: Megaloblastic anemia is due to the deficiency of the
maturation factor called folic acid  anemia. 

5. Aplastic anemia: Aplastic anemia is due to the disorder of redbone
marrow.

6. Anemia of chronic diseases: Anemia of chronic diseases is the second common type of anemia. It is characterized by a short lifespan of RBCs, caused by a disturbance in iron metabolism or resistance to erythropoietin action  

Identification of Anemia  

Anemia is identified by the finding of a hemoglobin concentration or hematocrit that is below the normal range. 

This usually presents little difficulty in the clinical situation since symptoms only occur in individuals with moderate or severe anemia. 

On the other hand, prevalence studies of nutritional anemia depend on the identification of mild anemia in an otherwise healthy population. 

The World Health Organization (WHO) criteria established in 1975 are the most widely accepted. 

Hemoglobin concentrations below 13 g dl−1 for adult males, 12 g dl−1 for menstruating women, and 11 g dl−1 in pregnancy are considered indicative of anemia.

The following tests are useful in the indication of Anemia

• Complete Blood Count (CBC), which determines the number, size, volume, and hemoglobin content of red blood cells
• Blood iron level and your serum ferritin level, the best indicators of your body's total iron stores
• Levels of vitamin B12 and folate, vitamins necessary for red blood cell production.
• Special blood tests to detect rare causes of anemia, such as an immune attack on your red blood cells, red blood cell fragility, and defects of enzymes, hemoglobin, and clotting
• Reticulocyte count, bilirubin, and other blood and urine tests to determine how quickly your blood cells are being made or if you have hemolytic anemia, where your red blood cells have a shortened life span

Only in rare cases will a doctor need to remove a sample of bone marrow to determine the cause of your anemia.

In this following video clip: Anemia is discussed very throghly, people from any department can know about Anemia

Causes of anemia

Different types of anemia have different causes. They include:

• Iron deficiency anemia. This most common type of anemia is caused by a shortage of iron in your body. Your bone marrow needs iron to make hemoglobin. Without adequate iron, your body can't produce enough hemoglobin for red blood cells.

  Without iron supplementation, this type of anemia occurs in many pregnant women. It is also caused by blood loss, such as from heavy menstrual bleeding, an ulcer, cancer and regular use of some over-the-counter pain relievers, especially aspirin, which can cause inflammation of the stomach lining resulting in blood loss.

• Vitamin deficiency anemia. Besides iron, your body needs folate and vitamin B-12 to produce enough healthy red blood cells. A diet lacking in these and other key nutrients can cause decreased red blood cell production.

  Also, some people who consume enough B-12 aren't able to absorb the vitamin. This can lead to vitamin deficiency anemia, also known as pernicious anemia.

• Anemia of inflammation. Certain diseases — such as cancer, HIV/AIDS, rheumatoid arthritis, kidney disease, Crohn's disease and other acute or chronic inflammatory diseases — can interfere with the production of red blood cells.
• Aplastic anemia. This rare, life-threatening anemia occurs when your body doesn't produce enough red blood cells. Causes of aplastic anemia include infections, certain medicines, autoimmune diseases and exposure to toxic chemicals.
• Anemias associated with bone marrow disease. A variety of diseases, such as leukemia and myelofibrosis, can cause anemia by affecting blood production in your bone marrow. The effects of these types of cancer and cancer-like disorders vary from mild to life-threatening.
• Hemolytic anemias. This group of anemias develops when red blood cells are destroyed faster than bone marrow can replace them. Certain blood diseases increase red blood cell destruction. You can inherit a hemolytic anemia, or you can develop it later in life.
• Sickle cell anemia. This inherited and sometimes serious condition is a hemolytic anemia. It's caused by a defective form of hemoglobin that forces red blood cells to assume an abnormal crescent (sickle) shape. These irregular blood cells die prematurely, resulting in a chronic shortage of red blood cells.

General Symptoms  of Anemia 

Anemia signs and symptoms vary depending on the cause. If the anemia is caused by a chronic disease, the disease can mask them, so that the anemia might be detected by tests for another condition.

Depending on the causes of your anemia, you might have no symptoms. Signs and symptoms, if they do occur, might include:

• Fatigue
• Weakness
• Pale or yellowish skin
• Irregular heartbeats
• Shortness of breath
• Dizziness or lightheadedness
• Chest pain
• Cold hands and feet
• Headaches

At first, anemia can be so mild that you don't notice it. But symptoms worsen as anemia worsens.

Treatment

There is a range of treatments for anemia. Each aims to increase the number of RBCs, which, in turn, increases the amount of oxygen in the blood.

Below, we outline treatments for several types of anemia:

• Iron-deficiency anemia: Iron supplements and dietary changes can help, and, when relevant, a doctor will identify and address the cause of excessive bleeding.
• Vitamin deficiency anemia: Treatments can include dietary supplements and vitamin B-12 shots.
• Thalassemia: Treatments include folic acid supplements, iron chelation, and, for some people, blood transfusions and bone marrow transplants.
• Anemia due to chronic disease: The doctor will focus on resolving the underlying condition.
• Aplastic anemia: Treatment involves blood transfusions or bone marrow transplants.
• Sickle cell anemia: Treatment typically involves oxygen therapy, pain relief medication, and intravenous fluids, but it can also include antibiotics, folic acid supplements, blood transfusions, and a cancer drug called hydroxyurea.
• Hemolytic anemia: The treatment plan may include immunosuppressant drugs, treatments for infections, and plasmapheresis, which filters the blood.

Summary

Anemia occurs when a low number of RBCs are circulating in the body. This reduces the person’s oxygen levels and can lead to symptoms such as fatigue, pale skin, chest pain, and breathlessness.

There are over 400 types of anemia. Common causes are blood loss, reduced or impaired RBC production, and the destruction of RBCs.

The most common type is iron-deficiency anemia. It sometimes develops due to a diet lacking in nutrients, Crohn’s disease, or the use of certain medications.

A doctor can use a CBC blood test to help detect anemia. Treatment varies, depending on the type, but it may include iron or vitamin supplements, medications, blood transfusions, and bone marrow transplants.

However, for some people with anemia, dietary changes can resolve the issue.