What Causes Red Blood Cells to Get Small?
                                
                                
                                •
                                
                                
                        
                                    
                                    3 min read                                
                            
                                Microcytosis, the medical term for smaller-than-normal red blood cells, is most commonly caused by iron deficiency. These small, or microcytic, red blood cells often contain less hemoglobin, which can lead to fatigue, weakness, and other symptoms of anemia. Understanding the various factors that influence red blood cell size is the first step toward diagnosis and effective treatment.