ALL ABOUT ANEMIA- SYMPTOMS, CLASSIFICATION, AND HOW TO TREAT

DEFINITION OF ANEMIA

Anemia is a disease in which there is reduction in the number of red blood cells less than 4 million/microliter or decrease in the amount of hemoglobin less than 12gm/dL or both.

The deficiency of hemoglobin results in decreased capacity of blood to carry oxygen to body tissues.

Anemia primarily affects women and children.

The name anemia is derived from ancient Greek [ (an)- not and (haima) – blood].

PREVALENCE

PREVALENCE IN INDIA

According to the National Family Health Survey (2019 – 2021), the prevalence of anemia in India is as follows –

IN CHILDREN ( 6 – 59 months) – 67.1%

IN WOMEN ( 15 – 49 years) – 57.0 %

ADOLESCENT GIRLS ( 15 – 19 years) – 59.1 %

MEN ( 15 – 49 years) – 25 %

GLOBAL PREVALENCE OF ANEMIA

Anemia affects 24 – 25 % of the worldwide population.

Sub Saharan Africa and South Asia have the highest prevalence of anemia in the world.

GRADING OF ANEMIA

• MILD ANEMIA – Hemoglobin 8 – 12 gm/dL
• MODERATE ANEMIA – Hemoglobin 5 – 8 gm/dL
• SEVERE ANEMIA – Hemoglobin less than 5 gm/dL

SYMPTOMS OF ANEMIA

• Fatigue
• Breathlessness
• Palpitations
• Pale skin
• Dizziness
• Reduced exercise tolerance
• Loss of concentration
• Irritability
• Headache
• Repeated chest infections
• Generalized body ache
• Spoon shaped nails
• Mouth ulcers
• Restless leg syndrome

BLOOD, HEMOGLOBIN AND RED BLOOD CELL INDICES

TOTAL BLOOD VOLUME – 5 to 6 liters ( 8 % of body weight or 80 mL/kg body weight).

FUNCTIONS OF BLOOD

• Transport of oxygen from lungs to tissues and of carbon dioxide from tissues to lungs.
• Carries glucose, vitamins, amino acids, fatty acids, electrolytes and other absorbed food materials from the alimentary canal to the tissues.
• Transfer of metabolic wastes like urea, uric acid, creatinine to kidney, skin and intestine for their excretion.
• Maintains internal environment of the cell known as Millieu Interieur. Blood is responsible for preserving volume, concentration, composition, temperature, pH of cell. This process is called Homeostasis.
• Maintains normal body temperature.
• Contains humoral antibodies that play important role in immunity.
• The clotting factors in blood regulate Haemostasis.
• The plasma proteins in blood perform functions like exchange of fluid and formation of transport complexes.

HEMOGLOBIN

Hemoglobin is a red colored pigment present in the red blood cells of vertebrates. It carries oxygen. It consists of iron containing pigment ‘haem‘ and the protein ‘globin‘.

Haem is an iron containing porphyrin, called iron – protoporphyrin IX. The iron in haem is in the ferrous form ( Fe²⁺ ). Each Fe²⁺ combines with one molecule of oxygen.

The polypeptide globin consists of two alpha and two beta chains. Each alpha chain contains 141 amino acids and each beta chain contains 146 amino acids. One molecule of hemoglobin has 4 haem so 4 iron atoms and can therefore carry 4 molecules ( eight atoms ) of oxygen.

NORMAL VALUES OF HEMOGLOBIN

Adult males – 14 – 18 gm/dL

Adult females – 12 – 15.5 gm/dL

14.8 gm/dL is regarded as 100% hemoglobin.

FUNCTIONS OF HEMOGLOBIN

• Helps in transport of oxygen from lungs to tissues and of carbon dioxide from tissues to lungs.
• Acts as an important buffering agent. 70% of buffering capacity of blood is because of hemoglobin.
• Hemoglobin binds with nitric oxide in lungs which causes vasodilation when released in tissues.

NORMAL VALUE OF RED BLOOD CELL

Adult males : 5 – 6 million/microliter (average – 5.5 million/microliter).

Adult females – 4.5 – 5.5 million/microliter (average – 4.8 million/microliter).

5 million/microliter is regarded as 100% RBC count.

LIFE SPAN OF RBC – Normal life span of RBC is 120 days.

RBC INDICES (BLOOD STANDARDS)

MEAN CORPUSCULAR VOLUME (MCV)

The volume of a single RBC in femtoliter is known as MCV.

MCV = Ten times packed cell volume per 100 mL of blood divided by RBC count (in million/microliter).

*Packed cell volume represents the cellular elements of blood (RBCs, WBCs and platelets).

NORMAL VALUE = 90 fL (78 – 94 fL).

• RBCs with normal MCV – Normocytes
• RBCs with lower than normal MCV – Microcytes
• RBCs with higher than normal value – Macrocytes

MEAN CORPUSCULAR HEMOGLOBIN (MCH)

It is the average amount of hemoglobin present in a single RBC in picogram.

MCV = Ten times value of hemoglobin (in gm/dL) divided by RBC count (in million/microliter).

NORMAL VALUE = 30pg (28 – 32 pg).

MEAN CORPUSCULAR HEMOGLOBIN CONCENTRATION (MCHC)

It is the concentration of hemoglobin in a single RBC.

MCHC = Hundred times hemoglobin value (in gm/dL) divided by packed cell volume per 100 ml of blood.

NORMAL VALUE = 33% (32 – 38%).

• RBC with normal MCHC – Normochromic
• RBC with lower than normal MCHC – Hypochromic

TYPES OF ANEMIA

ETIOLOGICAL CLASSIFICATION OF ANEMIA

HEMORRHAGIC

Anemia caused by blood loss

• Acute – due to sudden loss of blood
• Chronic – chronic blood loss due to piles, worm infestation, menstrual blood loss, peptic ulcer.

ANEMIA DUE TO DIETARY DEFICIENCY

Deficiency of iron, proteins, vitamins.

DYSHEMOPOIESIS

Due to abnormality in blood production. This results in decrease in all types of blood cells – RBCs, WBCs and platelets. It causes aplastic anemia.

• X – rays irradiation
• Gamma rays irradiation
• Hypersensitivity of bone marrow to chemicals, sulpha drugs, cytotoxic drugs.

HEMOLYTIC ANEMIA

Anemia caused by excessive destruction of red blood cells.

INTRACORPUSCULAR / INTRINSIC DEFECTS

Intra-corpuscular defects are hereditary in nature.

• Congenital spherocytosis
• Hemoglobinopathies – sickle cell anemia, thalassemia
• Erythroblastosis fetalis
• Glucose-6-phosphate dehydrogenase (G6PD) deficiency

EXTRACORPUSCULAR / EXTRINSIC DEFECTS

These defects are of acquired type.

• Infections like malaria
• Antigen-antibody reaction
• Drugs / poisons – quinine, aspirin, snake venom, burns
• Hypersplenism – increased destruction of red blood cells

MORPHOLOGICAL CLASSIFICATION OF ANEMIA

MICROCYTIC (MCV < 80 fL)

• Iron deficiency anemia
• Thalassemia
• Anemia of chronic disease
• Sideroblastic anemia

MACROCYTIC (MCV > 100 fL)

• Megaloblastic anemia – Vitamin B12 deficiency, Folic acid deficiency.
• Alcoholic liver disease

NORMOCYTIC (MCV 80 – 100 fL)

LOW RETICULOCYTE

• Aplastic anemia
• Bone marrow failure
• Myelofibrosis
• Leukemia
• Renal failure
• Anemia of chronic disease

HIGH RETICULOCYTE

• Sickle cell anemia
• G6PD deficiency
• Hereditary spherocytosis
• Autoimmune hemolytic anemia
• Paroxysmal nocturnal hemoglobinuria

IRON DEFICIENCY ANEMIA

Commonest type of anemia worldwide.

As the haem portion of hemoglobin is made up of iron so, deficiency of iron results in decreased hemoglobin production, causing anemia.

CAUSES

• Consuming less iron in diet.
• Acute hemorrhage.
• Chronic hemorrhage – due to peptic ulcer, piles, worm infestation, increased menstrual blood loss.
• Increased demand in pregnant women, infants, children, during menstruation.
• Diseases of stomach and duodenum resulting in reduced absorption of iron.

SYMPTOMS

• Lack of energy/ fatigue
• Shortness of breath
• Paleness of skin
• Palpitations
• Headache
• Loss of concentration
• Craving for non food substances like ice, dirt, clay ( known as pica)
• Spoon shaped nails (koilonychia)
• Thin and brittle nails

INVESTIGATIONS

• MCV, MCH and MCHC – decreased (Microcytic hypochromic)
• RBC count – decreased or normal
• Peripheral blood smear – anisocytosis (change in size of RBCs) and poikilocytosis (change in shape of RBCs)
• Bone marrow – Normoblastic hyperplasia
• Serum iron – decreased

TREATMENT

• DIETARY MANAGEMENT – Increasing consumption of iron rich foods like green leafy vegetables, meat, beans, lentils, nuts. Addition of vitamin C rich food increases iron absorption.
• ORAL IRON SUPPLEMENTS – Ferrous sulphate, ferrous fumarate, ferrous gluconate.
• INTRAVENOUS IRON – Administered when oral iron is not tolerated or when there is malabsorption. Iron sucrose is most commonly used.
• INTRAMUSCULAR IRON
• TREATING UNDERLYING CAUSE – Treatment of peptic ulcer, worm infestation, piles or any other predisposing cause.

PERNICIOUS ANEMIA

It is caused by vitamin B12 deficiency. Vitamin B12 is absorbed in ileum with the help of intrinsic factor.

CAUSES

• AUTOIMMUNE – Auto antibodies destroy parietal (also known as oxyntic) cells of stomach which produces intrinsic factor (a glycoprotein which helps in absorption of vitamin B12).
• MALABSORPTION – Gastric bypass surgery, chronic atrophic gastritis, damage to ileum.

SYMPTOMS

• Fatigue
• Tingling and numbness in hands and feet
• Motor imbalance
• Confusion
• Depression
• Loss of memory
• Nusea
• Diarrhoea
• Shortness of breath
• Palpitations
• Magenta tongue – smooth due to loss of papillae, red in color

*Neurological symptoms are due to subacute combined degeneration of spinal cord.

INVESTIGATIONS

• RBC Count – reduced (often < 1 million/microliter)
• MCV and MCH- raised (Macrocytic normochromic)
• Peripheral blood smear – marked anisocytosis and poikilocytosis
• Reticulocyte count – > 5% (normal is <1%)
• Life span of RBC – decreased
• Serum bilirubin – >1 mg/dL
• Serum iron – increased (because iron is not utilized by immature RBCs)
• WBCs and platelets – decreased
• Bone marrow – Megaloblastic hyperplasia
• Plasma concentration of vitamin B12 – decreased

TREATMENT

• Vitamin B12 injections
• Oral supplements
• Dietary intake of meat, fish, eggs, dairy products
• Treating underlying cause

*Treatment prevents further progression of CNS damage but cannot reverse damage done already. (So called pernicious anemia meaning destructive or injurious).

FOLIC ACID DEFICIENCY ANEMIA

CAUSES

• Decreased dietary intake
• Malabsorption as in celiac disease, gastric surgery
• Increased demand during pregnancy
• Medications such as methotrexate

SYMPTOMS

• Fatigue
• Pale skin
• Dizziness
• Shortness of breath
• Sore tongue
• Confusion
• Depression
• Cognitive difficulties (in severe cases)
• Neural tube defects like spina bifida

INVESTIGATIONS

• MCV and MCH – Raised (Macrocytic normochromic)
• Serum folate – low
• Peripheral blood smear – Macro-ovalocytes and hyper-segmented neutrophils
• Bone marrow – megaloblastic hyperplasia

TREATMENT

• Oral folic acid supplementation
• Increased dietary consumption of folic acid rich foods like green leafy vegetables, legumes.