Packed red blood cells are red blood cells that have been collected, processed, and concentrated for transfusion purposes. However, there are several synonyms for packed red blood cells that healthcare professionals should be familiar with. These include concentrated red blood cells, packed cells, packed red blood, packed cells volume (PCV), hematocrit (Hct), and erythrocyte concentrate. All these terms refer to the same blood product, but the choice of which term to use may depend on the context or healthcare setting. Regardless of the synonym used, packed red blood cells play a crucial role in the treatment of various medical conditions that require increased oxygen-carrying capacity.