Final answer:
Anemia is defined as a decreased oxygen carrying capacity of the blood due to inadequate red blood cells or hemoglobin. It causes symptoms like weakness and is often due to blood loss, lack of RBC production, or RBC destruction. Polycythemia, on the other hand, involves an overproduction of RBCs leading to increased blood viscosity.
Step-by-step explanation:
The decreased oxygen carrying capacity of the blood is defined as anemia. This is a condition in which there is an inadequate volume of red blood cells (RBCs) or hemoglobin, leading to a reduction in the blood's ability to carry oxygen to the body's tissues, potentially causing symptoms like weakness and fatigue.
Anemia can occur due to various reasons such as significant blood loss, which could be from an acute situation like a hemorrhage, or from a chronic condition that causes slow blood leakage.Inadequate production of red blood cells can also lead to anemia, which might be due to nutritional deficiencies like iron, vitamin B12, or folate. Another cause is the destruction of red blood cells, which can occur in conditions like sickle cell anemia, where the abnormal crescent shape of RBCs prevents normal circulation and delivery of oxygen.
In contrast to anemia, a condition known as polycythemia occurs when there is an overproduction of red blood cells. This can cause the blood to become too viscous, making it harder for the heart to pump and can also lead to increased blood pressure and other complications.