Final answer:
The medical term for decreased oxygen in the blood is hypoxemia. It is often associated with conditions like anemia, where the oxygen-carrying capacity of the blood is compromised due to inadequate hemoglobin or red blood cells.
Step-by-step explanation:
The medical term for a condition of decreased oxygen in the blood is hypoxemia (option c). Hypoxemia signifies a lower-than-normal level of oxygen in the blood, specifically in the arteries, which can lead to symptoms of weakness and fatigue. Conditions like anemia, sickle cell anemia, and thalassemia can contribute to hypoxemia as they affect the blood's capacity to effectively carry oxygen. Anemia is characterized by an inadequate volume of red blood cells or hemoglobin, which is paramount for oxygen transport from the lungs to tissues. Sickle cell anemia, in particular, involves red blood cells that are misshapen (crescent-shaped) and rigid, impeding their passage through capillaries and diminishing oxygen delivery to tissues. Thalassemia is another genetic disorder that results in an abnormally low level of hemoglobin, reducing the oxygen-carrying capacity of the blood.