Anemia : Type, Symptom, Causes, Diagnosis, And Treatment

Anemia is a decrease in the amount of red blood cells or hemoglobin in the blood or a lowered ability of the blood to carry oxygen.Red blood cells carry hemoglobin, an iron-rich protein that attach to oxygen in the lungs and carry it to tissues throughout the body.Diagnosing in men is based on a hemoglobin of less than 130 to 140 g/L (13 to 14 g/dL), while in women is less than 120 to 130 g/L (12 to 13 g/dL).Sickle cell anemia is an inherited hemolytic anemia in which the hemoglobin protein is abnormal, causing the red blood cells to be rigid and clog the circulation because they are unable to flow through small blood vessels.Hydroxyurea (Droxia and Hydrea) drug is used to treat sickle cell anemia.

The Types of Anemia

• Anemia due to blood loss includes Trauma and Gastrointestinal Bleeding.
• Anemia due to decreased red blood cell production includes Iron Deficiency, a Lack of Vitamin B12, Thalassemia, and a number of neoplasms of the bone marrow.
• Anemia due to increased red blood cell (RBC) breakdown includes a number of genetic conditions, such as Sickle Cell Anemia, Infections like Malaria, and some Autoimmune diseases.

The Causes of Anemia may be classified :

1. Anemia of Impaired red blood cells production.

• Disturbance of proliferation and differentiation of stem cells : pure red cell aplasia, aplastic anemia, anemia of renal failure by insuffecient erythropoietin production, anemia of endocrine disorders.
• Disturbance of proliferation and  maturation of erythroblasts : pernicious anemia, anemia of prematurity, anemia of folic acid deficiency, congenital dyserythropoietic anemias.

2. Hemolytic Anemias are anemia of increased red blood cells (RBCs) destruction.

• Intrinsic (intracorpuscular) abnormalities : hereditary spherocytosis, hereditary elliptocytosis, abetalipoproteinemia, hemoglobinopathies, paroxysmal nocturnal hemoglobinuria.
• Extrinsic (extracorpuscular) abnormalities : antibody-mediated, mechanical trauma to red cells.

3. Hypervolemia is anemia of blood loss and fluid overload.

Blood loss :

• Trauma or surgery
• Gastrointestinal tract lesions
• Gynecologic disturbances
• Infections by intestinal nematodes feeding on blood, such as hookworms.
• Menstrution in young women and older women with fibroids.

Fluid overload causes decreased hemoglobin concentration :

• Excessive sodium or fluid intake, sodium or water retention and fluid shift into the intravascular space.
• Anemia with pregnancy is induced by blood volume expansion experienced in pregnancy.

The classification of Anemia based on the size of red blood cells :

1. Microcytic Anemia is primarily a result of hemoglobin synthesis failure/insufficiency, which could be caused by several etiologies :

• Heme synthesis defect : iron deficiency anemia.
• Globin synthesis defect : Alpha-thalassemia and beta-thalassemia, HbE syndrome, HbC syndrome.
• Sideroblastic defect : hereditary sideroblastic anemia, aquired sideroblastic anemia (lead toxicity), reversible sideroblastic anemia.

2. Macrocytic is if the cells are large.It can be caused by removal of the functional portion of the stomach, such as during gastric bypass surgery, leading to reduce vitamin B12 or folate absorption.

• Megaloblastic anemia is due to a deficiency of either vitamin B12 of folic acid or both.
• Hypothyroidism
• Alcoholism
• Drugs like Methotrexate, Zidovudine, and other substances may inhibit DNA replication, such as heavy metals.

3. Normocytic occurs when the overall hemoglobin levels are decreased, but the red blood size (corpuscular volume) remains normal.Its causes include :

• Acute blood loss
• Anemia of chronic disease
• Aplastic anemia (the failure of bone marrow)
• Hemolytic anemia

4. Dimorphic. A dimorphic appearance on a peripheral blood smear occurs when there are two simultaneous populations of red blood cells, typically of different size and hemoglobin content (this last feature affecting the color of the red blood cells on a stained peripheral blood smear.

5. Heinz Body Anemia forms in the cytoplasm of red blood cells and appears as small dark dots under the microscope.

6. Hyperanemia is a severe form of anemia, in which the hematocrit is below ten percent.

7. Refractory Anemia is an anemia which does not respond to treatment.

The Symptoms of Anemia

• Loss of conciousness
• Weakness
• Feeling tired
• Shortness of breath
• Increased thirst
• Pale or yellow skin
• General malaise
• Poor concentration
• Palpitations
• Bone deformities
• Chest pain
• Headache
• Dizziness
• Cold hands or feet
• Pounding or whoosing in ears
• Fast or irregular heartbeat

Diagnosis

Anemia is diagnosed on a complete blood count.

• Flow cytometry is an important tool in distinguishing between the causes of anemia.
• Examination of a stained blood smear using a microscope.
• Parameters, such as Red Blood Count, Hemoglobin Concentration, MCV, RDW, Hematocrit, MCH, and MCHC.
• If the cause is not obvious, the clinicians use some tests, including ESR, Ferritin, Serum Iron, Transferrin, Red Blood Cell (RBC) Folate Level, Serum Vitamin B12, Hemoglobin Electrophoresis,  and Renal Function Test (Serum Creatine).
• If diagnose remains difficult, A bone Marrow Examination allows direct examination of the precursors to red cells.It is reserved for cases where severe pathology needs to be determined or excluded.

Treatment Of Anemia

Treatments for anemia depend on cause and severity of disease.

• Vitamin supplements, such as folic acid or vitamin B12 are given orally or vitamin B12 is given intramuscularly that will replace specific deficiency.
• Oral Iron supplementation with ferrous sulfate, ferrous fumarate, or ferrous gluconate can treat mild to moderate iron-deficiency anemia.
• Injectable iron or Parenteral iron.Parenteral iron can be used where iron absorption is impeded or in cases of inflammation.
• Blood Transfusions should be undertaken in cardiovascular instability cases.People with coronary artery disease are recommended to transfusion if the hemoglobin is below 70 to 80 g/L (7 to 8 g/dL).
• Erythropoiesis-Stimulating Agent (ESA) is to maintain hemoglobin at the lowest level that both minimizes transfusions and meets the individual person needs.It should not be used for mild or moderate anemia.People with chronic kidney disease are not recommended unless hemoglobin levels less than 10 g/dL or they have anemia symptoms.It is used in severe anemia.
• Hyperbaric Oxygen (HBO) is used to indicate when oxygen delivery to tissue is not sufficient in patients who cannot be given transfusions for medical or religious reasons.It may be used for medical reasons when threat of blood production incompatibility or concern for the factors of transmissible disease.Hyperbaric Oxygen is used in severe anemia.
• Thalassemia can be treated with blood transfusions, folic acid supplements, medications, and removal of the spleen (Splenectomy) or a blood or bone marrow stem cell transplant.