Anaemia is a medical condition characterized by a decrease in the number of red blood cells (RBCs) or a reduction in the amount of hemoglobin within the red blood cells.
Haemoglobin is an iron-containing protein that binds to oxygen, allowing RBCs to transport oxygen from the lungs to the rest of the body.
When anaemia occurs, the body's tissues and organs receive less oxygen, leading to fatigue, weakness, and shortness of breath.
Types of Anaemia
1. Hemorrhagic anemia:
Blood loss due to injury, surgery, or internal bleeding (e.g., from ulcers, tumors, or heavy menstrual bleeding).
2. Hemolytic anemia:
Premature destruction of RBCs, either due to inherited conditions (e.g., sickle cell anaemia, thalassemia) or acquired factors (e.g., autoimmune diseases, infections, certain medications, or toxins).
3. Anemia due to decreased or defective RBC production:
Lack of essential nutrients (e.g., iron, vitamin B12, folic acid) or bone marrow disorders affecting RBC production.
Examples:
A. Iron-Deficiency Anaemia:
The most common form, usually caused by inadequate iron intake, poor absorption, or blood loss.
B. Vitamin-Deficiency Anaemia:
Caused by deficiencies in vitamin B12 or folic acid, leading to impaired RBC production.
Pernicious anaemia is a specific type of vitamin B12 deficiency due to a lack of intrinsic factor, necessary for vitamin B12 absorption.
C. Aplastic Anaemia:
A rare condition where the bone marrow fails to produce enough RBCs, white blood cells, and platelets.
Causes include radiation, chemotherapy, certain medications, or autoimmune diseases.